Hoooo boy!
Given how many characters I have, most of them never used in RP, well, I could write novels. As to those characters I have played? For my Nassquill character Onin Bey, I just "realized" that he plays a flute in his quiet moments. I've already known for some time that my Nism character Deen was a "wild child" in his youth, always getting into trouble. His mate, Thoee... well, she's very fond of music and dance, but I've never brought out that side of her in RP. Yet.
I could go on, but I'm running out of time on this library computer, so I'll have to... heh... continue later. Gotta have time to think of more, as well. Later, then...