okay, there are three categories here. one is younger artists that wouldn't overlap with his acting career (alexander giannascoli, tor miller, bill wurtz--the last one was a vine guy which could mesh with what you have written in his bio), one is artists closer to his age (noah gundersen, adam baldwin) and one is artists that are a bit older that you might be able to just claim partial credits (dan mangan, chris garneau).
there were a lot of english indie musicians so i tried to stay within america/canada but if you want any of those options, i can go back and dig a bit deeper!