I hope this question is appropriate on this SE. Maybe it's a bit of a trivia but somehow I see it as part of music history.
So Glenn Gould's humming is notorious and does not need to be discussed. What I would like to know (and I could not find any testimony about this) is if it did bother the musician sitting more or less close to him during live concerts.
I wonder if other musician may have found that distracting or annoying during practice or even more so during the real concert. Somehow it's a thought that made me very curious and I wonder if anyone has some reference to share about this.