Gould

[beethovenopus2no3movt2]

You can listen to his music and suddenly be lost in the music due to his beautiful Humming.

[j_menz]

his beautiful Humming.

His "beautiful humming" annoys the heck out of me!

[forte88]

For someone that mastered WTK 1&2 by the age of 8, 3 or 4 voiced polyphony isn't enough to keep it interesting, so he adds his own voice as well

[asuhayda]

I think from what I've read, he developed that habit because his mother was his teacher when he was young and she told him to do it. Apparently, he thought he was a pretty good singer... he was wrong. 

He's still a genius in my opinion. 

[landru]

I second the learning-from-mother/teacher theory - I heard it in a documentary as well. Let's just that we are fortunate that his mother didn't come from a click-language region in south or east Africa!

It's one thing that he's doing it, but sometimes he's out of tune! But yes, he is still a master and if we have to put up with that humming, so be it.