A little while back, concerning a performance of Bach on PS, someone made the oft heard statement "Pedal should not be used in Bach becase Bach didn't have a pedal". (Not an exact quote but I've heard, and even uttered that basic idea for years). I jokingly said to myself "Mozart didn't have pedals either." He did have knee controls for the dampers.
So I decided to first try to discover when some form of damper control was added to the piano. And since I was thinking of the pianos at the time of Bach, I decided to explore what other devices, effects, and so forth would have been on the piano at that time and with which Bach may have had experience. Obviously the information that I have collected needs further research and documentation, but this isn't a dissertation so I will just report what I have collected.
First, the players:
1. Bartolomeo Christophori (May 4, 1655 – January 27, 1731)
2. Gottfrieb Silbermann (14 Jan 1683 - 4 Aug 1753)
3. Johann Sebastian Bach (21 March 1685, O.S. [31 March 1685, N.S.] – 28 July 1750, N.S.)
Note that Silbermann was born about 2 years before Bach and died about 3 years after Bach.
Christophori is said to have invented the piano in the early 1700's. It was invented by 1709 when Scipione Maffei did research on the newly invented piano, including an interview with Cristofori, and published his findings (with a ringing endorsement of the instrument) in a 1711 Italian journal article.
Christophori's pianos were double strung throughout its range. It is said that fairly early in Christophori's develpment of the piano he added an "una corde" device. This consisted of a hand knob at either end of the keyboard which the performer used to slide the entire action to the right (just as on the modern grand, except that we do it by pedal) in order to play just one string for each key. Of course, if the una corde was engaged, it would need to be used through and entire movement, or at least a section that had a substantial pause in the music to allow time to slide the keyboard the other way.
In 1725, the Maffei article was translated into German by the Dresden court poet Johann Ulrich König, who was almost certainly a personal acquaintance of Silbermann. Sometime after this, Silbermann acquired Christophori's design and built the same type instrument. I have seen it said that he had acquired an earlier design that did not have improvements made by Christophori, particularly the "inverted wrest plank", which from what I can tell has to do with the tuning pins and tuning stability.
Evidence from the Universal-Lexicon of Johann Heinrich Zedler indicates that Silbermann first built a piano in 1732. This was a year after Christophori had died so the design and improvements were set. The question remains if the design that Silbermann had contained the plan for the "una corde" device. (Bach was in Leipzig, age 47). From this point, except for the 3 years between Bach's death and Silbermann's death, anything that Silbermann had added to the piano could well have been on the pianos with which Bach had experience.
It is not clear when Bach actually first saw the piano. Johann Friedrich Agricola (musician and son-in-law to Bach), tells a story about the relationship of Silbermann, Johann Sebastian Bach, and pianos. After Silbermann had completed two instruments, Agricola says, "Silbermann showed them to Bach, who replied critically, saying that the tone was weak in the treble and the keys were hard to play. Silbermann was stung and angered by the criticism, but ultimately took it to heart and was able to improve his pianos (exactly how is not known, but it may have been the result of Silbermann's encountering Cristofori's most mature instruments). The improved Silbermann pianos met with Bach's "complete approval". So it could have been as early as the 1732 date.
[An momentary aside: First, though Agricola is not clear when Bach first saw Silbermann's pianos, it seems to imply that it was rather early in Silbermann's work with pianos. It does make sense to me that Silbermann would want Bach's endorsement of the instrument as early as possible. Though Bach was considered old school in his compositions, he was well known and admired as a virtuoso keyboard performer. An endorsement by Bach for this new instrument surely couldn't hurt sales.
Second, often it has been written that "Bach disliked the piano at first". Personally I think this is an unfair assesment of Agricola's story. It has the connotation of an old fuddy-duddy saying "why do we need this new-fangled contraption." Bach loved the clavichord because of its dynamic nuances. Why would he not be interested in an instrument that had similar nuances available, but could be used in a larger venue? He was also known to combine organ stops in unusual ways that were not "by the book", not part of the organ design, and that would make the builders cringe, expecting a bad effect, when Bach's registrations would ultimately provide wonderful sound combinations.
In the case of these early pianos, Bach gave a specific critique. Silbermann listened and Bach approved.
Third, Bach may have had more personal experience with the piano than we had thought. Apparently a preserved sales voucher dated May 8, 1749 shows that Bach acted as an intermediary for Silbermann in the sale of at least one of his pianos. I would love to see that sales slip, or go into a piano store and be greeted by Bach.]
During the 1740s, King Frederick the Great of Prussia became acquainted with Silbermann's pianos and bought a number of them (the early 19th century musicologist Johann Nikolaus Forkel claims this number was 15, though Stewart Pollens believes this to be "certainly exaggerated"). According to one source that I found, when Bach visited his son, C.P.E Bach in Potsdam, King Fredrick took him on a tour of the pianos in his palaces. It was on a piano that Bach first improvised on King Fredrick's theme that would later become "A Musical Offering". (So is this actually a piano piece by Bach???)
After all of that you probably thought that I forgot about the damper. Not so. Guess what -- Silbermann invented a device by which the player could lift all of the dampers off the strings, permitting them to vibrate freely, either when struck or sympathetically when other notes were played!!! Could any of the pianos that Bach was familiar with have had this control??? Quite possibly, so though he didn't have a pedal, he may well have had some control of the dampers.
Silbermann's device was different from the modern damper pedal in two respects. First, it was not actually controlled by a pedal, but rather was a hand stop, which required the player to cease playing on the keys for a moment in order to change the damper configuration. Thus, it was a device for imparting an unusual tonal color to whole passages, rather than a means of nuanced expression as the pedal is today. Second, Silbermann's device was bifurcated, permitting the dampers of the treble and bass sections to be lifted separately.
The device would obviously need to be used on a piece with slow harmonic changes (such as the first prelude of WTC1 -- which of course could not have been written with this in mind). Since the pianos of the day did not have near the resonance, it would not have been such a noisy mess that it would be on todays instrument. Consider that this is the basic effect that Beethoven asks for in the first movement of the "Moonlight".
In conclusion, while this information gives no more justification to use the damper pedal in modern performances of Bach's music on the piano, it does somewhat deflate the blanket statement that one should never use it because his instruments did not have a "pedal". In the end it still comes to interpretive choices based on the needs of the music.