I'll expose myself here. It's Olivia and I think I put up a semi-decent bio on the first post if you want to take from that.
As far as piano goes, Jonas isn't exactly great on piano. He hasn't taken any lessons and the guys mostly write the songs on guitar. I believe I mentioned how his range is as wide as it is, in the story fo how he learned to sing the way he does. On top of that he worked in post-production for the film industry to help pay for the bands endeavors. He learned a lot from that experience as well and still doubles as a visual artist.