Actually, that's probably the reason why Music *isn't* their +25% skill: if it had been designed that way then the power scaling of instruments would have been slower to match because what you currently get out of 100 skill is the intended cap on its potential. End result: you get a 'skill bonus' that's actually a red herring.

If music was not a class-exclusive skill and there were instruments that could be used by non-bards then there might be a case for making it their bonus skill, but the presence of non-bard music and instruments would greatly weaken the identity of the class. The gadgeteer doesn't have the same problem with modern weapons since the skill itself isn't really class-defining for him.

100% you know how much practice it takes to master an instrument? It's definitely a skill, no question. I'd like to see a bard with a Fender Strat and a Marshall stack \m/ \m/ cranked to 10. That'd be the real "Sonic Boom".