Yeah, that's what I was thinking as well, not really a bard, but some kind of priest/monk.
Uses prayers to deliver confidence and motivation, which then would give boost in certain areas.
But, I like your idea of a bard that plays instruments, I might even consider that idea.
Music is so powerful, it sends a powerful message that a human would translate into some form of confidence and motivation.
Just one catch, how would they attack?