There is a lot of information about Glen Gould on the Internet. I was never interested in finding out about him because he hummed a lot on the LP record I have of him playing the French Suites by J.S.Bach. However recently I decided to find out more about him. It is interesting that he became very good at a finger technique he learned from a well recognized teacher in Canada. It was a detached sound suited to baroque music. His playing of polyphonic music was admirable. When he was in his mid twenties he had a successful concert tour in Russia.
One student said that her father told her she had to learn the piano for ten years.
An adult student said she never understood legato until she came to me, and I explained that for a very short time there were two notes down on the key bed together before the first note was released.
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.