"Guest, your list, " (accordians, melodeons, bagpipes, bodhrans, drums")
enforces the idea that economics, more than aesthetics, are behind jokes about musical instruments"

(I was the Guest who forgot to sign in)

I don't know what you mean - are you saying these instruments are cheap (low-status) or expensive (Elitist)? Or what?? Have you seen the price of good quality melodeons, bagpipes etc.? Or the price of a good full drum kit? There's hardly an instrument that isn't made fun of, usually in a good-natured way (check out Les Dawson's piano playing) - and I am probably not the only former double bass player who was always greeted with "Can you get that under your chin?". Have a look at this page of bagpipe jokes and see if there are any that haven't been applied to banjos or any other of the instruments I mentioned: http://www.rampantscotland.com/humour/blhumpipes.htm

It's just a case of (usually) fellow musicians taking the mickey out of each other - no need to look for race or class explanations.