Dudes, this shouldn't even be a house rule issue. Attaching bells to a mace is something a kid could do. Native American war clubs and tomahawks were frequently decorated with beads, feathers, medicine pouches, etc. You can find Asian & African blades & polearms with metal rings that jingle in museums. For that matter, warriors worldwide and all through history up to the modern riot-gear equipped policeman have used their weapons & shield as improvised drums to intimidate their foes.*
The difference between an escrima fighting stick and a similarly sized rhythm stick? Ridges. That won't change the force of a blow struck with one.
Sure, it lets you have something that is 2 things at once, but so do wizards & monks with their walking sticks/quarter staves/wizard staffs. The difference is everyone EXPECTS those to be dangerous in a FRPG. Besides, it does so realistically, and usually at the cost of not being easily able to move silently. And making music with something most people wouldn't it is the very kind of thing I'd expect a Bard to be able to do.**
To be clear, there are things I like about 5th, but this kind of thing bugs the bejesus out of me. Besides, I have 70+ other systems I can play with, so, while I feel bad about abandoning the game that got me into the hobby in '77, that feeling will pass.
Paraphrasing Rival Sons' "Good Luck": well, its gonna hurt right now but later it won't even cross my mind.
Sorry to derail.
* by this point, I'm pretty sure that there is no rule for an improvised instrument.
** anyone ever make a comb harmonica? Familiar with the origins of the glass armonica? Seen the guy who makes flutes out of carrots? Or see Frank Zappa play the bicycle on the Steve Allen show?