I'd say make a sense motive to figure out what the bard is up to with his her or their performances. Bard songs aren't magic they're supernatural their just so good at them they have an effect which can be likened to magic.
I found the right place to post this now, and don't know if anyone has asked this before. I am going to run The Lost Star with two PC's, and while scaling the elite monsters, I was wondering if you would need to make the elite adjustments multiple times for a larger change in characters?
Just replying so I can track the topic as I'm going to run a solo game with an NPC controlled by me and would like to know the same.