Thanks @AustenNut and @compmom for your replies. He has visited both campuses—he liked both, and could see himself at either one, but felt like day to day life might be “easier” at Oberlin given its size and small
town location. Ann Arbor was bustling and fun and exciting, but I think he wondered how he would adapt to the size of the campus, taking buses, etc. I also wonder about student support—is there a chance he might “fall through the cracks” at a place like Michigan if he is not yet the best advocate for himself. It would definitely be an opportunity for personal growth!
He was accepted into the BFA program at Michigan. Although he is quite an accomplished instrumentalist, he did not want to pursue a performance degree or prepare an audition on his instrument(s), so did not apply for the BM in music and technology. His focus is on the creative side, composition specifically. He composes on a DAW, and incorporates sounds that he records (acoustic instruments played by himself or others, sounds generated using various objects in the environment, singing, etc.) and manipulates these with the software, although some of his pieces are purely electronic, if that makes sense. I would not describe what he composes as sound art.
He wants to continue playing his instrument (percussion) in college, and sounds like he could do that at both places although he might not be eligible for all ensembles or for faculty lessons (perhaps depending on availability and audition results). He is very involved in marching percussion; to do that at a higher level as part of university life I think Michigan would be the place (he says this is not a deal breaker though).
He goes to a very large public high school where there is little individual attention so the idea of him going to a small private college is appealing (to me) although maybe he would get that experience as part of a smaller college at UMich (SMTD).
As a parent worried about career and job possibilities down the line I am glad he was accepted to the dual degree program at Oberlin. He did not apply to any college besides SMTD at UMich, although maybe he could do that later on? I am not sure how easy that is to do, or how competitive it might be.
Lastly, but importantly—finances. UMich ends up being considerably more affordable (about half the cost) than Oberlin, even without considering the fifth year of the double degree program. We can make it work without loans if it is the best place for him.