You might want to check on the official Disney Pins website (
www.disneypins.com?) for the official rules for trading with a WDW-CM. I don't think the musical pins are actually technically tradeable (like plastic pins aren't technically tradeable - I think the pins are supposed to be metal (with the copyright Disney on the back, etc), but I could be wrong.
As a Guest, I wouldn't trade for them, mostly because the batteries wear out and aren't replaceable. Once the music stops, it *really* stops.
agnes!