A local band in my little town just did this a few days back: guerrilla show at the local Salvation Army (in Ann Arbor, Mi). I think many of the instruments were toys and things the store had "on the shelves". His band is called The Rainbow Vomit Family Band, but they are calling themselves the Junkyard Hangover Band in this video (probably because they were hung over and playing crap at the thrift store).