I usually refer to them as a "herd" - for want of anything better. "Collection" isn't really a good description for them, since they all do get played - even the banjo. Well, the ones that are actually playable, anyway. To me "Collection" refers to things that don't get used. I can't think of anybody who uses their coin or stamp collections, for instance. If they did, they wouldn't have a collection for long... but you get the idea. "Herd seems to be a better term...
