So for the longest time, I've had an idea for a Bard and when the announcement for 2ed came, I decided that my first character would be this Bard. Now that I have the CRB, it seems like I can rather easily do what I want, but one new thing seems iffy, so I figured I'd ask about it. IT's no big deal if it doesn't work, but it would be interesting.
My Dwarven Bard (gasp, a Charisma flaw!) will be a sword (or more precisely, as pick) and board combatant who sings his songs to inspire his allies, thumping his weapon into his shield like a drum. For the most part, casting is fairly simple, since Somantic components can now be done while holding something in hand. But Bards are able to substitute Somantic components with playing an instrument. Can I beat on my shield for this, or will I have to rely on waving my pick and shield around while casting?
Ask your GM if he'll allow it, but by the rules I think you need a real instrument.
Considering that there exists a cleric feat that lets you go "lol, my armor/weapon is a holy symbol now because I drew on it, so I don't need a real one" I'm going to go with "no you can't do that."