Many teachers, performers and adjudicators of exam and competition students insist that because the sustain pedal did not exist on the instruments for which Bach wrote, it therefore should neither need to be used, nor be used when playing his works on the modern pianoforte.
This kind of reasoning, to be consistent, could lead one to conclude that performers on the modern day pianoforte have no place playing the music of J.S. Bach on it because none of his keyboard works were written for the newly invented gravicembalo col piano e forte (the first of the keyboards that could change the volume by varying the touch).
Musicians must settle this question for themselves, but assuming that the player does want to play the works on a modern pianoforte, the question of how to approach the use of pedal arises. The question for performers on the modern piano is how to use the pedal in a way that honours the spirit of Bach’s music.
In my experience, there are a few misconceptions at the heart of this debate:
First, that pianists would use the pedal in the same way as they would in nineteenth century music
Second, that harpsichords, clavichords and older keyboards are not resonant and that the sound is dry
Third, that the construction of the piano is basically the same as the older keyboards
Fourth, that physical legato lines are both possible and ideal in the music of J.S. Bach
In the first case, nineteenth century pedalling is primarily is used to create massed sonorities such as in this example:
Example: Liszt Orage, bars 20 to 27
The pedal also makes multilayered left hand harmonic textures possible where there is no possibility of physical connection over such wide distances and further where there three distinct textural layers – the bass voice, the melody voice and the inner voices – and yet the pianist only has two hands to accomplish such a texture.