Since the majority of these CNR instruments simply give bonus bard spell slots, could we lift the "bard-only" requirement on them so that other classes can feasibly cross-class perform and hold them for RP purposes? Unless somebody is a bard with bard spells, they wouldn't get much of bonus in gameplay in using them anyhow. Allowing other classes to pick them up and Roleplay that they have some limited musical talent if they'd like would be fun for characters. (ranger hippies strumming a guitar singing about the environment, whimsical eastern monks playing pan flutes, orcs doing tribal drums in a circle and helping their shamans perform ceremonies, etc)
Music is a large part of cultural identity and a frequent pasttime for warrior poets and the like. Sure you may have to be a bard to inspire somebody magically, but no great mystical force should shock a man's hand to drop a guitar if he's not a professional musician. If that happened, then nobody would be able practice with them long enough to become professionals.
