Vol. 110 (2021)

The Stephanie Chase Conversations:
Fine Musical Instrument Expert, Restorer & Author 
Stewart Pollens


By Stephanie Chase

Guest Columnist

New York, NY, USA


New York City-born Stewart Pollens is an authority on historical musical instruments. His work includes restoration, analysis, and scholarly publication, and it embraces keyboard instruments as well as historical stringed instruments such as the violin and lute. For over thirty years he was the conservator of musical instruments at The Metropolitan Museum of Art, where he was responsible for the maintenance and repair of more than five thousand instruments from all over the world, including ethnographic examples. The British conductor and violinist Andrew Manze has called him "one of the world’s foremost authorities on musical instruments," and his work has been recognized by American Musical Instrument Society, which awarded him a Nicholas Bessaraboff Prize. Pollens is the author of many articles and books on musical instruments that include The Violin Forms of Antonio Stradivari (Biddulph, 1992), The Early Fortepiano (Cambridge University Press, 1995), Giuseppe Guarneri del Gesù (Biddulph, 1998), Stradivari (Cambridge University Press, 2010), The Manual of Musical Instrument Conservation (Cambridge University Press, 2015), and Bartolomeo Cristofori and the Invention of the Piano (Cambridge University Press, 2017)His next book, A History of Keyboard Instruments, will be published by Cambridge University Press in the late winter of 2021.



STEPHANIE CHASE: You have a fascinating book coming out that is on the history of keyboard instruments, and it is your fifth published by Cambridge University Press. How broad a topic is this?


STEWART POLLENS: This book delves into stringed-keyboard instrument history from the very beginning through the present day and includes not only the development of the modern piano but the late-nineteenth and twentieth-century revival of the harpsichord, clavichord, and fortepiano.



STEPHANIE CHASE: What are the earliest known examples?


STEWART POLLENS: We know from documentary sources that keyboard instruments first appeared in the fourteenth century. The earliest depiction of them is found in a cathedral altarpiece carving in Minden, Germany dating from around 1425. In that carving three angels are playing a clavichord, a keyboard instrument having a bentside, probably fitted with a plucking mechanism, then termed a clavisimbalum, and a psaltery, which was a rudimentary plucked-stringed instrument without keyboard that preceded the clavisimbalum. The keyboard instruments in this carving are small enough to have been played on one’s lap or carried under an arm.

Clavisimbalum in Minden

STEPHANIE CHASE: Would you explain the basic mechanical differences between a harpsichord, clavichord, and piano, and why early pianos are sometimes called “fortepianos” and later ones “pianofortes?”


STEWART POLLENS: The harpsichord employs a plucking mechanism consisting of jacks bearing plectra that were traditionally made of bird quill or leather; the clavichord has thin metal blades projecting from the key levers that simply touch the strings; and the piano uses a striking mechanism, usually in the form of pivoted or hinged hammers. When Bartolomeo Cristofori developed his piano in Florence around 1700, it was initially called an Arpicimbalo che fa il piano e il forte, Italian for “harpsichord that makes soft and loud,” which describes that instrument’s ability to play gradations of soft and loud—something the harpsichord could not do. “Piano” and “forte” were joined to form “pianoforte,” which makes more sense than the abbreviated “piano.” For some reason, when speaking of pianos made in German-speaking lands, the order is reversed and the instrument is referred to as a Fortepiano, which is used today primarily in reference to wood-framed pianos, typically fitted with German- or Viennese-style hammer actions, that date from the late-eighteenth through early-nineteenth centuries. English pianos made during that time and later are generally referred to as pianofortes.

Cristofori Piano

STEPHANIE CHASE: The piano is generally believed to be a later invention. Where does it fit in historically?


STEWART POLLENS: A manuscript, written in Burgundy around 1440 by Henri Arnaut of Zwolle, describes and illustrates various forms of keyboard instruments that can be fitted with harpsichord and clavichord mechanisms as well as with a striking mechanism, which indicates that the piano was not a later development but was contemporary with the earliest harpsichords and clavichords. For some reason, the striking mechanism fell by the wayside until it was revived centuries later. The earliest extant examples of harpsichords and clavichords date from the early-sixteenth century. In my book The Early Pianoforte I describe a sixteenth-century Italian spinet that appears to have been converted into a tangent-action piano before Cristofori’s invention. If I am correct, that converted spinet would be the earliest known example of a piano.

STEPHANIE CHASE: What is the earliest known music for a keyboard instrument?


STEWART POLLENS: The so-called “Robertsbridge fragment” dates from around 1360 and can be played on any instrument with a keyboard. It was rediscovered in the mid-19th century in England.



STEPHANIE CHASE: Let’s turn to more recent history: for over thirty years you maintained and restored all types of instruments for The Metropolitan Museum of Art. What kinds of keyboard instruments did you work on there?


STEWART POLLENS: The Museum’s collection is encyclopedic and includes not only Western instruments but ethnographic instruments from around the world. My responsibility as the sole departmental conservator was to care for all these instruments. I worked on everything from a Sesando—a bamboo and palm leaf zither from Timor—to the Appleton pipe organ, which is an American instrument from 1830, though my principal training and expertise was in keyboard instruments and violins. The Museum’s keyboard instrument collection is extensive and, in many ways, the strongest aspect of the entire collection. I don’t recall the precise number of keyboard instruments, but I believe there are over 150.



STEPHANIE CHASE: What are the oldest keyboard instruments in the Museum’s collection?


STEWART POLLENS: The earliest keyboard instrument that I worked on was an Italian spinet dated 1540 made for Eleonora d’Este, the Duchess of Urbino. I also worked on harpsichords and clavichords made through the eighteenth century by various members of the Ruckers family, Ioseph Ioannes Couchet, John Crang, Christian Kintzing, Jacob Kirckman, Michele Todini, and Girolamo Zenti, among others. Then there were the early pianos; these include the oldest known example dated 1720 made by the widely acknowledged inventor of the piano, Bartolomeo Cristofori, Viennese fortepianos made by makers such as Ferdinand Hofmann, Joseph Böhm, and Conrad Graf dating through the 1830s, and late-eighteenth and early-nineteenth century English grands and squares made by Broadwood and the London branch of the Erard firm. By work, I mean ground-up restorations, both rudimentary and complex repairs, general maintenance, as well as tuning, voicing, and regulating for countless museum concerts and recordings. Among the first recordings I worked on were two LPs featuring the 1720 Cristofori piano played by Mieczysław Horszowski.

Italian Spinet (1540)

STEPHANIE CHASE: I’m glad you mentioned Horszowki. He was a formidable pianist who started out as a renowned child prodigy and was in residence at the Marlboro Music Festival at least one summer that I was there. Horszowski lived to be one hundred years old and is noted for having had the longest career of any classical musician. He married for the first time at age eighty-nine —to an Italian pianist who was forty years younger than he—and I recall them walking around the campus and holding hands. He was very short so she towered over him, and it was such a sweet thing to see. His desire to record on a fortepiano indicates his musical curiosity, because most modern pianists would not attempt that.


STEWART POLLENS: He was delightful to work with--very gentle and soft spoken—not what I expected from such a legendary figure. He had first performed on the Cristofori piano decades earlier, and it was interesting observing him getting re-acquainted with it after so many years.



STEPHANIE CHASE: What about later keyboard instruments at the Museum, and what kind of work did you perform on these instruments?


STEWART POLLENS: I also worked on modern pianos made by Bechstein, Bösendorfer, and Steinway, but it was mostly tuning, voicing, and action regulation. To do major work on these instruments often necessitates removing an enormous metal plate that requires a chain hoist. That’s where I draw the line!



STEPHANIE CHASE: Speaking of drawing; what drew you to the field of musical instrument making and conservation?


STEWART POLLENS: It was mostly my infatuation with the harpsichord literature, primarily the late-seventeenth century school of Chambonnières, Louis Couperin, and D’Anglebert. I apprenticed in harpsichord making with John Challis, later worked in organ building, and then went on to do graduate work in museum studies at City College (CUNY) and in conservation at the Institute of Fine Arts (NYU). I also hold a certificate issued by the Mittenwald Violin Making School course held at the University of New Hampshire.

Chaconne by Louis Couperin - Excerpt 
(Stewart Pollens)


STEPHANIE CHASE: The Mittenwald School is a renowned program that dates back to the 17th century in Bavaria.


How did you arrive at your position at the Metropolitan Museum?


STEWART POLLENS: In 1975, while serving a graduate internship in the Department of Musical Instruments, I catalogued the Museum’s collection of some 100 pianos and was hired on a free-lance basis to do conservation work on a group of instruments for an upcoming exhibition in 1776, The World of Franklin and Jefferson. This included casework on one of the earliest pianos made in America, a square by Charles Albrecht of Philadelphia, repair of an eighteenth-century porcelain flute, stringing and gilding repairs on an eighteenth-century harp, and setting up a wreck of an Amati violin that had just been donated to the Museum. I recall that I also did some keyboard-instrument tuning during that time as well. While an intern, I invited the head of the Department of Musical Instruments to my apartment to play the copy of the Metropolitan Museum’s Cristofori piano that I had just made as a studio project at City College—perhaps that impressed him. I was appointed staff conservator in 1976 and worked there through 2006.


Cristofori under construction

STEPHANIE CHASE: What are some of the conservation issues that are particular to keyboard instruments?


STEWART POLLENS: Probably the most controversial issue surrounding historic musical instruments is the “play or preserve” debate. At the Metropolitan Museum there simply was no debate: the curatorial decision was to “play,” so I was tasked with restoring and maintaining instruments for use in regular gallery demonstrations, Patrons’ Lounge events, formal concerts in the Museum’s various concert halls, and even up at the Museum’s branch at the Cloisters. Unfortunately, this fell largely upon the keyboard instruments, for the Museum did not possess a quartet of bowed-stringed instruments that could have served for chamber music concerts, as was the case at the Library of Congress and Smithsonian Institution. There is just so much one can do with a kettle drum or conch-shell trumpet to entertain the Park Avenue crowd.



STEPHANIE CHASE: Unfortunately, it is in moving pianos around that they tend to get damaged – even in museums.


STEWART POLLENS: That’s true. When a three-hundred-year-old harpsichord is lifted off its stand it typically makes groaning and creaking noises. It always pained me to have to move them from one end of the building to another and up and down stairs; I would oversee these moves, which were officially the responsibility of the Museum’s riggers, to prevent mishaps. So often were keyboard instruments moved around that I used to joke that the freight elevator was my office. After I left the Museum, I was invited to contribute to an in-house publication that deals with the safe handling of art objects.



STEPHANIE CHASE: What is the process for determining how, or even if, a keyboard instrument should be restored?


STEWART POLLENS: The “if” question must be considered first. For example, in 1996, I participated in a conference held at the Händel-Haus Museum in Halle, Germany, to consider whether their Hans Ruckers harpsichord, made in 1599, should be restored or left in an unrestored state. My contribution was published in Kielinstrumente aus der Werkstatt Ruckers (1998). I was also invited to participate in a similar conference regarding the possible restoration of a Cristofori spinet, dated 1690, that was held at the Galleria dell’ Accademia in Florence; my proposal was published in Restauro e conservazione degli strumenti musicali antichi (2008). In certain instances, an instrument may be so rare or significant in some way that restoring it might compromise its value as an historical study piece. Assuming there are no ethical considerations involved, one first addresses structural and soundboard concerns before turning one’s attention to stringing and coaxing ancient keyboards and mechanical parts to work. The adverse effects of time and wear and tear must be dealt with, such as the twisting of case structures due to string tension, general shrinkage and warpage of wooden parts, and halting woodworm activity. Mechanical parts made of wood, leather, cloth, and metal often become embrittled, decayed, moth-eaten, or corroded and may have to be replaced with suitable materials to restore playability. Finding those materials is often difficult or even impossible, as manufacturing processes may have changed or disappeared. Replacing these crucial ephemeral parts is where “authenticity” often gets compromised.



STEPHANIE CHASE: Woodworm alone sounds like a nasty problem for a museum object.


STEWART POLLENS: Yes, it is. When the larvae of these insects have finished boring through wood—and they may gnaw away for years—the mature adults fly off and lay their eggs on another object. When I was first working at the Museum, there was a fumigation chamber that used a chemical pesticide. Towards the end of my days there, another system was developed termed “anoxic disinfestation,” which uses oxygen scavengers and an atmosphere of inert argon gas to kill the woodworm eggs and larvae. It is safer as far as museum objects are concerned than the use of chemicals or another popular procedure involving heat and humidity. I describe an accessible adaptation of the anoxic technique in my book, The Handbook of Musical Instrument Conservation.

STEPHANIE CHASE: It’s clear that you’ve kept up with the scientific end of conservation work! What are some other factors guiding keyboard restoration?


STEWART POLLENS: What must be given careful consideration are historical alterations and previous restorations; in some instances, one would not want to restore an instrument to its original state if an historical alteration is worthy of being retained. An example of this would be a seventeenth-century Flemish harpsichord that was enlarged in Paris in the eighteenth century by the addition of a second keyboard and widening the keyboard range, a process the French termed ravalement. On the other hand, poorly executed repairs or ill-advised restorations should be corrected or undone, though often the damage is irreversible. One must also consider deliberate or inadvertent changes made to string lengths, which are often revealed when ultraviolet light causes glue marks left by originally positioned bridges and nuts to fluoresce.



STEPHANIE CHASE: So, you use more recent technologies for some of these investigations?


STEWART POLLENS: Yes; for example, the condition of internal bracing and soundboard ribbing can be ascertained by x-raying the instrument or by use of endoscopy. Material analysis can be carried out by such techniques as x-ray fluorescence and gas chromatography/mass spectroscopy. I made use of an epi-fluorescence microscope to study the stratification of Stradivari’s violin varnish and a polarizing microscope to identify pigments; for example, those used in the case and lid painting of the 1581 Ruckers double virginal at the Met.

Ruckers double virginal (1581)

STEPHANIE CHASE: To follow up on Stradivari’s varnish, because that has been the focus of centuries of speculation, what did you learn?


STEWART POLLENS: Stradivari used two distinct layers of varnish; the underlying layer was relatively clear and uncolored, and the top layer was pigmented. This can be easily seen, even with a hand-held magnifying glass under ultraviolet light in areas that have worn away—what appears is a fluorescent milky, straw-colored halo of the underlying varnish beneath an upper varnish that fluoresces a salmon color. Gas chromatography/mass spectroscopy indicated that Stradivari employed a simple oil varnish composed of linseed oil and pine resin; the pigment in the samples I examined was red ochre, a naturally occurring earth pigment that is principally iron oxide, though there were also traces of an organic colorant. I go into this in greater detail in my book, Stradivari.

STEPHANIE CHASE: These investigations of instruments provide a wealth of information, but you must know not only how to go about them but how to interpret what is revealed.


STEWART POLLENS: The “forensic” examination of early keyboard instruments is one of the most fascinating aspects of this work—opening up an early harpsichord and peering into a structure that was last seen by its maker three hundred years earlier is tremendously exciting and ultimately edifying; for example, by observing and charting the direction and overlap of glue drips, one can establish the construction sequence. On the interior of one Neapolitan harpsichord, I discovered evidence of a little fire that the maker had made with a pile of wood shavings heaped on the instrument’s bottom boards—I suspect the maker did this either to dry out the soundboard so that it would bulge upwards slightly and form a crown upon re-absorbing moisture from the air after it was glued in place, or perhaps to keep the hot animal-hide glue from chilling as the soundboard was dropped in. 



STEPHANIE CHASE: This sounds like real detective work! How do you identify the work that you, yourself, have performed on an instrument, for the scholars of the 22nd century?


STEWART POLLENS: Museum conservators are expected to keep records of their interventions and to store and catalog any parts that are removed. If feasible, new parts are marked and dated. Towards the end of my tenure at the Met, the Museum was in the throes of computerizing its catalog records, though despite my protestations there was no facility for incorporating conservation reports in the Musical Instrument Department’s digital catalog. I sincerely hope that my binders of conservation reports and photographs have been preserved. One reason I wrote The Manual of Musical Instrument Conservation was to document the techniques I employed while at the Met out of concern that my museum records might disappear. Some museums, such as the British Museum, include conservation reports in their online catalogs; the Met does not.



STEPHANIE CHASE: That’s unfortunate, because future scholars will not have complete information on these and other Museum objects. It reminds me of the axe that eventually has its handle replaced and, later, the blade. The idea of the original remains but the object is completely altered.


Of the keyboard instruments that you worked on at the Metropolitan Museum, which ones stand out?


STEWART POLLENS: Maintaining the Cristofori piano of 1720, the oldest extant piano made by the purported inventor, was a great thrill. It was featured in numerous recordings and gallery events.



STEPHANIE CHASE: It was my pleasure to play a concert there with that piano, although it was tuned extremely low – something like a minor third below normal  and I had to adapt.


STEWART POLLENS: That is due to it having been improperly restrung by a predecessor—I was never given permission to restring it according to my research findings. My properly strung copy, however, could be tuned up to Baroque pitch and was featured on a radio program.



STEPHANIE CHASE: What are some of the other notable keyboard instruments in the collection?


STEWART POLLENS: The Museum has a superb collection of sixteenth- and seventeenth-century Flemish virginals and harpsichords; my technical study of early alterations made to them was published in The Metropolitan Museum Journal in 1997. The Museum’s so-called “Golden Harpsichord,” made by Michele Todini in the 1670s was also of great interest to me. It was originally termed the Machine of Galatea and Polyphemus when it was installed by its maker in his Galeria Armonica in Rome. My technical examination of that instrument was the subject of a paper published in The Metropolitan Museum Journal in 1990.

"Golden Harpsicord" by Michele Todini

I was also involved in the Museum’s acquisition of a Conrad Graf fortepiano made in Vienna around 1838. I promoted its purchase because it was an excellent example in unrestored condition—it even had its original strings. The Museum’s director at the time, Philippe de Montebello, released acquisition funds only after I agreed to restore it to playability. It needed extensive soundboard repairs, and I had to figure out how to repair cracks, re-glue the loose bridge and underlying ribs while retaining the original strings—an interesting problem. I published a report on this restoration in Chopin et son temps [2010] and in my Manual. Incidentally, I recall your recital performance of Beethoven’s “Kreutzer” Sonata with Anthony Newman at the Museum shortly after I completed the restoration. You were using one of the Museum’s Stradivari violins, which was an excellent match for the Graf’s powerful tone.

Conrad Graf fortepiano (circa 1838)

STEPHANIE CHASE: It was a pleasure to play with Tony and that extraordinary piano, and what I remember best is that it was the fastest “Kreutzer” I ever played – and will remain that.


When I view an instrument at a museum, I am usually seeing just its exterior, and I would imagine that this is a major factor in doing museum restoration.


STEWART POLLENS: One of the challenges of working on old keyboard instruments involves restoring their appearance, which is especially important in a museum environment where instruments are placed on exhibition. This might involve fabricating missing casters, hinges, bolt covers, ormolu mounts and moldings, replacing missing or damaged veneer, and carving or turning missing legs. Varnished and painted surfaces must be cleaned and retouched, which often involves gilding, French polishing, and other furniture-making techniques.



STEPHANIE CHASE: It sounds like in addition to having a breadth of knowledge and skills, you’ve worked with a lot of equipment.


STEWART POLLENS: My workshop at the Museum not only included conventional woodworking tools like chisels and planes, but also a machine lathe, jeweler’s lathe, drill press, milling machine, silver-soldering and welding torches, electro-cleaning and plating equipment, as well as a system for filtering and de-ionizing water. There was also a full complement of precision measuring instruments, such as micrometers, vernier calipers, bore gauges, etc. For maintaining a photo archive, I used a large-format view camera, and generally black and white film, which was then considered more archivally stable than color—in fact, the Museum’s photo studio then used the same system for its record photos. I also produced many photos on infrared film and employed ultraviolet fluorescence photography to read faded inscriptions, glue marks, etc. In The Handbook of Musical Instrument Conservation, I describe in detail the tools and techniques I used for my work and its documentation.


In one case, where I felt my own technique might not be sensitive enough, I sent the nameboard of a sixteenth-century Italian spinet to the Jet Propulsion Laboratory to undergo a special type of photography termed “multi-spectral analysis.” Unfortunately, they got confused by my use of the terms “obverse” and “reverse” and wound up examining the wrong side of the nameboard, so my own imaging had to suffice. Evidently, they don’t have dictionaries in Pasadena.



STEPHANIE CHASE: It’s somewhat shocking that the rocket scientists didn’t know the difference – and didn’t think to ask you! But clearly, you have a multi-faceted approach to doing your research and documentation. 


STEWART POLLENS: Keyboard instrument restorers, or “conservators” as we are now called, are the museum professionals who wear smocks and get their hands dirty—like surgeons, we open up instruments in order to repair their inner workings and, like psychoanalysts, we attempt to discover the motivational processes that went into design and construction techniques, especially when they deviate from the norm. That is the mechanical side of keyboard research; then there is the historical aspect, such as discovering when and where makers lived and worked and with whom they apprenticed, as well as learning about guild regulations and patronage. Then of course there is the music—how did early-keyboard instruments suit the music of the period? Discovering which instruments were used by major composers and virtuosi invariably sheds light on their compositional style and performance practice.



STEPHANIE CHASE: How do you go about this?


STEWART POLLENS: For example, my research into the life and work of Bartolomeo Cristofori led me to the Medici archives in Florence. Documents preserved there enabled me to reconstruct, virtually on a month-by-month basis, his activities as a maker and restorer of keyboard instruments for his patron, Grand Prince Ferdinando de’ Medici, and to show how his work coordinated with musical activities at court. This research has been presented in two of my earlier books, The Early Pianoforte and Bartolomeo Cristofori and the Early Piano.

STEPHANIE CHASE: Royal and dynastic archives must be a great source of information, along with the usual census counts.


STEWART POLLENS: In the case of Cristofori, the Medici archives preserved in Florence proved a treasure trove. The Medici were bankers, so they documented any activity that involved money, which with Cristofori included his monthly stipends, payments for making new keyboard instruments and restoring others, and even reimbursements for expenses involved in moving instruments from one residence to another. Stradivari was not associated with a court, so in researching his life I had to rely primarily upon the census, church, and notarial records preserved in Cremona. Again, that research is presented in my book, Stradivari.



STEPHANIE CHASE: What are some of the technological developments that have altered the structures of keyboard instruments?


STEWART POLLENS: Without a doubt the two major technological advances in keyboard-instrument design and structure were the development of the cast-iron frame around 1825 and advances in the production of high-tensile strength steel wire, which took place in the second half of the nineteenth century. The cast-iron frame enabled the piano’s case to support greater string tension and to better stay in tune. Early iron wire, around which harpsichords, clavichords, and early pianos were designed, lacked the tensile strength required as the piano evolved in the nineteenth century. When modern steel wire was developed, piano makers were able to increase scaling of their instruments by some thirty percent and thereby improve tonal quality. Without high-tensile strength steel wire, the modern piano could not have come about—nor could the building of the Brooklyn Bridge!


Another important advance was the invention of the double-escapement action, also called the “repetition action,” patented in 1821 by the Érard firm. This action enables the player to repeat notes before the key has returned to its rest position. Érard’s invention is still employed in the modern piano.

Érard (Metropolitan Museum)

STEPHANIE CHASE: It sounds like pianos not only got larger – and louder – but also a lot heavier with the addition of a cast-iron frame.


STEWART POLLENS: True, a Viennese piano made in 1800 might have weighed around 150 pounds, whereas the cast-iron frame of a modern concert grand alone weighs around 300 pounds, contributing to a total weight of about 800 pounds.



STEPHANIE CHASE: In concert use, keyboard instruments have an essentially fixed pitch that needs to accommodate many different musical key signatures – in fact, Bach wrote his Well-Tempered Clavier to illustrate the qualities of a special tuning temperament – and over the centuries there have been many arguments over this matter. What are some of the characteristics of the more widely accepted tuning temperaments?


STEWART POLLENS: Keyboard instruments can be tuned up or down to a certain degree, and what they offer in distinction to fixed-pitch instruments is the ability to alter temperament, which involves subtle adjustments to the pitch of the notes comprising the musical scale. There are essentially two types of intonation: just and Pythagorean, the scale of the former is built upon simple, whole number ratios between a base note and the other notes in the scale; the scale of the latter is built up of notes generated by successions of perfect fifths and octaves. In the Renaissance, when stringed keyboard instruments were invented, there is documentary evidence that some were tuned in Pythagorean temperament, although by the beginning of the sixteenth century so-called “meantone temperament” came into wide use.



STEPHANIE CHASE: Could you define that?


STEWART POLLENS: Meantone corrects certain dilemmas encountered in just intonation—one being its two sizes of whole tones having ratios of 9:8 and 10:9 that together make up a 5:4 major third.



STEPHANIE CHASE: When you use ratios, you are describing the theoretical lengths of taut strings that produce pitches – the shorter being a higher pitch?


STEWART POLLENS: That’s correct. The term “meantone” refers to equalizing the size of the two adjacent whole tones that make up a third by taking the geometric mean of that interval. This is accomplished by narrowing the fifths. The human ear finds superparticular ratios, such as 5:4, more appealing than non-superparticular ratios, such as the Pythagorean third of 81:64, and in equal temperament the third is even less palatable, as the relationship between the two notes is an irrational cube root of 2 to one. Harpsichordists appreciate the difference between a meantone 5:4 third and an equally tempered one, but modern pianists don’t know any better as their only experience is with equal temperament.


Though meantone has sweeter thirds, it does have some major problems: one can’t play in all keys, and one leftover fifth is so wide and out of tune that it is called the “wolf fifth” because it sounds like the howling of a wolf. If you ever have access to a harpsichord tuned in meantone, play a G sharp together with an E flat and you will be struck by the discord. I go into this more clearly and in greater depth in my forthcoming book.



STEPHANIE CHASE: Meantone tuning must have been very restrictive for composers.


STEWART POLLENS: It was, though despite its defects, meantone persisted through the Baroque and beyond. Around J. S. Bach’s time, various temperaments were devised that not only enabled more key signatures to be used but that also “tamed” the wolf. These are sometimes referred to as “circulating temperaments” or “well temperaments.” Equal temperament, which is universally used today in tuning modern pianos, actually has much earlier roots—it was first mathematically approximated in China around 400 A.D., and in the West was used during the Renaissance in tuning lutes. It was not generally employed in tuning keyboard instruments until well after Bach composed his Well-Tempered Clavier, which is a work featuring all twenty-four major and minor keys that was intended to showcase the merits of some sort of circulating temperament. Though one can play in any key with equal temperament, it lacks certain distinctions between keys that illicit different moods, termed “affect.” The jury is still out as to which temperament Bach might have preferred.



STEPHANIE CHASE: I understand that the key signatures used by Bach in the more agitated movements are the ones that have greater inherent dissonance within the tuning system.


As a violinist, I find that in playing Classical music with the appropriate keyboard instruments of the era, issues of volume and voicing are not present, unlike with modern grand pianos. There is also a different timbre, or tonal quality that, ultimately, is extremely expressive. Why is this the case?


STEWART POLLENS: No instrument differs more from its predecessors than the modern piano. The violin, for example, is virtually unchanged since the sixteenth century, and aside from the addition of keys and valves, most woodwind and brass instruments are similar to those used in earlier times. The same cannot be said of the modern piano—this behemoth bearing some twenty tons of string tension and over seven octaves of keys is quite different from its ancestral forms. The volume of sound that it can produce is far greater than that of harpsichords and clavichords, and its timbre differs considerably from earlier forms of the piano. A manual published in 1802 for purchasers of fortepianos made by the Stein firm in Vienna states that a piano should have a tone “that resembles the best wind instruments,” and a similar guide published in 1824 by the Dieudonné and Schiedmayer firm in Stuttgart repeats this characterization and goes on to specify the clarinet and horn as models of good tone. This certainly cannot be said of the modern piano, which stands very much apart from orchestral instruments.



STEPHANIE CHASE: What are some of the reasons for this?


STEWART POLLENS: The timbre of pianos is the result of many factors: string lengths, string thicknesses, the striking points of the hammers, the weight of the hammers and the resilience of hammer-head coverings. Early pianos had smaller hammer heads covered with layers of soft leather, while the modern piano uses much heavier hammers covered with hard, highly compressed felt. Soundboard thickness and the bridge’s positional relationship to soundboard ribbing, as well as many other structural details, all influence tone. The fact that the modern piano lacks a case bottom, whereas early forms of keyboard instruments have one, also affects tonal quality, particularly in the bass. In the Viennese pianos of the late-eighteenth and early-nineteenth centuries, the crisp attack of their light-weight hammers, as well as their leathered, wedge-shaped dampers that snuff out sound with great immediacy, combine to provide a greater sense of articulation than can be achieved on the modern piano.



STEPHANIE CHASE: Those aspects are what I enjoy hearing in the early pianos, but they probably do not translate as well when heard in a large, modern-day concert hall.


You mentioned that you apprenticed with John Challis. Wasn’t he noted for making harpsichords with aluminum soundboards and frames? Tell us a bit about him and how he influenced you.


STEWART POLLENS: Challis was born in Ypsalanti, Michigan, and studied organ as a boy. After completing high school, he sailed to England and apprenticed with Arnold Dolmetsch, a harpsichord maker and important figure in the revival of Early Music.


When Challis returned to America in the late 1920s, he began making harpsichords and clavichords for clientele all over the country. As we know, the climate in the United States varies tremendously; there is the arid Southwest and tropical southern Florida, and central heating in apartments and houses in major northern cities invariably results in extreme dryness during the winter. Challis was fearful that his instruments would fail under this wide range of temperature and humidity.


In his youth, he had worked alongside his father, a clock maker, so he used his mechanical and engineering skills to devise a new type of case structure that could stand up to these extremes. Over his career, his instruments evolved, and he finally settled upon a light-weight frame of cast aluminum concealed below a soundboard made of honeycombed aluminum, a material used in the construction of commercial aircraft that has a mass-to-stiffness ratio similar to that of spruce, the traditional soundboard wood, but that would not swell, contract, or crack under changing humidity as does wood. Quite surprisingly, his instruments with aluminum soundboards sound very much like his earlier ones made of spruce—they do not sound “metallic” as one might suppose.



STEPHANIE CHASE: It is interesting to note that the tops of many stringed instruments are also made from spruce.


How else do Challis’s instruments differ from the traditional styles? Do they sound different?


STEWART POLLENS: His harpsichords and clavichords differ from those built on historic principles in their organ-like sustaining power and remarkable tuning stability. Challis’s mechanical parts, like harpsichord jacks and registers, were also fabricated of materials that would not swell or contract in changing humidity. He built his instruments to last an eternity; for example, he strung them with stainless-steel wire and used stainless-steel screws and pins to resist corrosion.



STEPHANIE CHASE: Were his unorthodox harpsichords accepted by performers?


STEWART POLLENS: Challis had great success with his instruments, which were used in many concerts and recordings—the most notable feature Scarlatti sonatas performed by harpsichordists Ralph Kirkpatrick and Fernando Valenti. The English organist E. Power Biggs ordered an elaborate pedal harpsichord from him and made several recordings using it, including his magnificent Bach on the Pedal Harpsichord and a wild recording of Scott Joplin.

STEPHANIE CHASE: I have a vague recollection of being on a concert tour as a teenager, and my collaborative pianist recognized Biggs in an airport! We spoke to him and, as I recall, he was carrying a single rose.


But back to Challis: Because his instruments were unorthodox in many ways, he must have also had a fair share of criticism?


STEWART POLLENS: This was true as the early music scene became more particular about “authenticity.” Challis defended his style of harpsichord making and staunchly believed “the harpsichord should have a future as well as a past.” He was a real character; for example, he was fanatically distrustful of the federal government and banks, having lost the proceeds of his first harpsichord sale in the “bank holiday” of ’29.  I was his last apprentice, and I credit him with giving me my start in this profession.



STEPHANIE CHASE: Does the Met’s collection contain any of his instruments?


STEWART POLLENS: Towards the end of my tenure there, I arranged for the Museum’s acquisition of Challis’s most ambitious project, a pedal harpsichord even more complex than the one he had made for Biggs—for example, it includes a 2’ stop in the pedal division! The last recording of any significance that I was involved with at the Museum was Anthony Newman’s recording of Bach organ music on that instrument. It was quite a challenge tuning the pedal harpsichord to the one above it, and I also recall having to make a replacement for a broken overwound string in the 2’ stop. From a physician who had treated Challis and acquired his workshop materials after his death, I borrowed the same coils of wire that Challis had used in making the original strings. As I recall, the brass winding of that 2’ string has a diameter of 0.0065”, a very fine gauge that is almost impossible to find today. 

Incidentally, Challis joked that he put in a 16-foot stop in order to “scare the ladies!” When all the stops of his concert-size harpsichords were engaged – 2x8’, 4’, 16’ – I must say the effect was somewhat like the pealing of church bells or a calliope, take your pick.



STEPHANIE CHASE: I’m not sure I’d describe a 16’ stop as scary, but the sound of that instrument is very impressive. Unlike violins, harpsichords have a huge number of moving parts and must be a challenge to design and fabricate.


STEWART POLLENS: In apprenticing with Challis, I developed woodworking and metalworking skills and learned a great deal about the workings of the harpsichord and clavichord, as well as the early piano, as Challis also became involved in making what he termed “Mozart pianos.” In developing a hammer action for those pianos, he constructed working models of piano actions based upon cross-sectional drawings in Rosamund Harding’s book The Piano-Forte, published by Cambridge University Press in 1933. I would take these models off a shelf in his workshop and study them during my lunch breaks. I must admit I had to pat myself on the back when I finally figured out how the modern piano action worked!


From Challis, I also learned the art of making jigs, which are devices used in fabricating duplicate parts—such as the hundreds of jacks used in harpsichords—as well as the many hammers and escapement parts used in pianos. One jig might be designed to drill a hole in the same place in hundreds of identical parts, while another might be used to trim those parts to exactly the same length. I should add that though I appreciated Challis’s ingenuity and admired his instruments, my own interest has always been in keyboard instruments built strictly on historic principles.



STEPHANIE CHASE: We should give a shout-out to Peter Fisk, a renowned American maker who built your double-manual harpsichord. Not only does it have a beautiful sound, it is also gorgeous.

Stewart Pollens playing Peter Fisk double-manual harpsichord

STEWART POLLENS: Yes, I am delighted with it, as I am with my Flemish single-manual harpsichord made in the Hubbard shop after an original by Hans Moermans dated 1584 that Frank Hubbard himself owned. My one regret is that I never had the time or workshop facilities to make my own harpsichord.



STEPHANIE CHASE: That would take a lot of space and equipment. But let’s move from harpsichords back to pianos. You recently published an article entitled “The Piano of the Future.” Tell us about it.


STEWART POLLENS: This appears in a compilation of articles on the piano entitled Clefs pour le piano published in 2018. In it I discuss the development of the modern piano and express my feeling that it has strayed too far from its origins and would benefit by restoring some of the piano’s earlier traits, such as employing a case bottom, using a continuous bridge and nut that provide greater continuity in terms of scaling and the proportionality of striking distance to string length, running the dampers up to the top string, and vastly simplifying the hammer action. I feel that the modern piano suffers from nineteenth century “patent fever” and in so doing became a victim of “progress.” By “patent fever” I am referring to the hundreds of patents feverishly taken out by piano manufacturers in the late nineteenth and twentieth centuries, many of which were frivolous.



STEPHANIE CHASE: That’s a good example of the axiom “new and improved,” as in increasing sales and making the previous version of something seem outdated.


We have focused on keyboard instruments, but over the course of your career you have maintained and restored hundreds of instruments of all types from throughout the world. What are some of the most challenging procedures you’ve had to perform, and some of the most historically interesting instruments?


STEWART POLLENS: For me, some of the most challenging procedures involve cosmetic restoration: retouching varnished and painted surfaces, freehand carving, and figuring out how to make mechanical parts by hand that match those originally made in factories by specialized machinery. To me, the most historically interesting instruments are the conventional ones, especially those made by major makers of the types owned and used by the great composers and virtuosi. I am less interested in odd-ball instruments like giraffe pianos and folding harpsichords. On the other hand, I have enjoyed working on some unusual projects, such as restoring Alice “In Wonderland” Liddell’s accordion and a tambourine painted by Toulouse-Lautrec.

Tambourine painted by Toulouse-Lautrec

STEPHANIE CHASE: And, as I recall, you did a complicated restoration of an oud owned by the fashion designer Mary McFadden.


STEWART POLLENS: Yes, I had to fabricate missing geometric elements in a variety of exotic woods and repair the most ornate ivory rosette I have ever encountered. I saved some of the leftover material as an example of my woodworking skills.



STEPHANIE CHASE: How has the pandemic affected your work as a researcher, writer, and musical instrument conservator?


STEWART POLLENS: Research involves traveling to archives, libraries, and museums, so that has unfortunately come to a complete halt. Writing about and restoring musical instruments are pretty much solitary occupations, so that continues for me as it did before the COVID-19 pandemic. Although public and university libraries have been closed, the internet, along with dealers in books, journals, dissertations, Festschrifts, and other research materials, remain active. I am grateful to the libraries throughout the world that have scanned so many old books, manuscripts, and scores, which are now available in facsimile on short notice and at reasonable prices. In many ways, research can be carried out more efficiently today—even during the pandemic—than several decades ago. During this period, I have also been doing some private conservation work on violins at my home workshop for a New Jersey museum; the only hitch is getting together to pick up and deliver instruments. I also just finished restoring an 1868 New York-made melodeon for my own use, which resides in our circa 1780 house in Connecticut.

Stewart Pollens and Galileo Telescope

STEPHANIE CHASE: You have already written an exhaustive series of books on conservation, Stradivari, the Paduan maker Cristofori, and a history of early fortepianos. What would you like to write about next?


STEWART POLLENS: I would like to write a history of the violin. Nothing like it exists, and I feel the time has come for such a work to be written by someone other than a violin dealer.


STEPHANIE CHASE: I look forward to this! Thank you for sharing your expertise with Stay Thirsty.


(Photographs of:  Cristofori piano, Italian Spinet piano, Ruckers double virginal, Todini harpsichord, Graf piano and Érard piano - Courtesy of Metropolitan Museum of Art)



Stewart Pollens   

Stephanie Chase    



Stephanie Chase

Stephanie Chase is internationally recognized as “one of the violin greats of our era” (Newhouse Newspapers) through solo appearances with 200 orchestras that include the New York and Hong Kong Philharmonics and the Chicago, San Francisco, Atlanta and London Symphony Orchestras. Her interpretations are acclaimed for their “elegance, dexterity, rhythmic vitality and great imagination” (Boston Globe), “stunning power” (Louisville Courier-Journal), “matchless technique” (BBC Music Magazine), and “virtuosity galore” (Gramophone), and she is a top medalist of the prestigious International Tchaikovsky Competition in Moscow. Recent concert appearances include music festivals in Newport, RI, Mt. Desert, ME, Hanoi and Ho Chi Minh City, Vietnam, Bargemusic, Music in Context (Houston), and as soloist with the New York Scandia Symphony.

All opinions expressed are solely those of its author and do not reflect the opinions of Stay Thirsty Media, Inc.