A musical one that got missed earlier:

Old Man with Mandolin (Guitar player paintings are soooooo common.)

Possible the only "musical" painting by Tamara Lempicka suitable for display in a public place (in the US); but I rather like it - and a couple of her guitar players. This one is a little less "art-deco" than much of her work.

The same site (mild nudity warning) has a fair but small selection of her other works. Much of her work was a bit "racy" for our unsophisticated US public, even now, almost a century later.

Note that this thread started in 2004, and lots of the links here probably have drifted to that famous "404 Club." It's likely that most of the paintings discussed can still be found, so asking for help with a link refresh, or for help with where/how to search, shouldn't be out of order.

John