Performing Bach on the Pianoforte

Bach's keyboard music was written for harpsichord and clavichord, as the pianoforte was not yet invented. When a key is depressed on the harpsichord a string is plucked and sounds for a short time after the key is released. When playing for example a fugue by Bach, sometimes it may be necessary to use the damper pedal on the piano to obtain legato between two notes. On the harpsichord the two sounds will sound connected as the sounds of the harpsichord continue for a brief time after the key is released.

Some pianists very rarely, if at all,  use the sustaining pedal when playing Bach.