I play piano and watching videos of Gould playing is fascinating. He violates every rule your piano teacher tells you about performance, from his unusually low chair made to accommodate a back injury to his habit of singing along to tunes that was often picked up in his album recordings. I especially like this performance of Beethoven's 32 variations in C minor by him [1].
[1] https://www.youtube.com/watch?v=UoWXRlw9vBA