It sounds like he might do really well in an artsy liberal arts college, or maybe a school that has few or no gen ed requirements and more freedom to choose courses. When he does apply I would encourage him to submit arts/music supplement including samples/recordings/videos of work, a resume related to the art/music, and letters or recommendation related as well.
Depending on the school, he can decide on major in late sophomore year, and major and career to not necessarily have to align. He can do performance, studio, internships, summer programs, volunteer- whatever helps clarify career goals- while in school.
Schools that come to mind include Brown, Amherst, Wesleyan (google “little Ivies”), Clark (google Colleges that Change Lives), Vassar, Skidmore, Hobart William Smith, Bennington, Lewis and Clark- many more…
Sounds like a great kid! He will find his way.
ps my kid who is a little similar didn’t think about college until fall of senior year- very frustrating- but ended up at Brown