Bob Dubois and others chastise Glen Gould:

>Ron Chaplin wrote:
>
>>I don't think Glenn Gould showed disrespect humming while performing.  He
>>probably couldn't help doing it.
>
>So he's a fool playing very well the piano but singing really irritating.

Glenn is not the only one to exibit this trait.  Jendo Jando on Naxos has
started to hum on some of his later recordings.  Particularly in the Haydn
series.

Could it just be that these guys love the music? After all every time I
enter a record store and a famous tune comes on half the customers seem
to hum along.

Bob Draper