These pieces are all early works--the first evidence of Bach's great mastery as a composer for the keyboard. A toccata comes from the Italian (and French, and Spanish) verb meaning "to touch" or "to play an instrument." It's a type of written down improvisation, in which the player "tries out" his instrument with passages requiring great speed, extremes of dynamic both loud and soft, and finally a sustained chunk of music in several parts, generally a fugue. As Gould is the greatest (and most eccentric) Bach pianist in history, his performances are powerfully persuasive. Most importantly, they have a freely improvisational quality which makes the music sound fresh and always surprising.