Besides music what other things is your son looking for in a college? Small versus Large, Urban vs College Town, East Coast vs West Coast, Competitive vs Less Competitive, Seminar classes vs Lecture classes, Progressive Liberal vs Conservative, Sports?, etc…all those things should play a role in his making his decision. The important thing is for him to land at a school where he can explore all the things he wants to explore (including with his music and his interest in law) while also socially happy and comfortable.
I can speak for the East Coast in that our high school had a very competitive and successful Jazz program and every year there were talented Jazz musicians who went off to LACs. Many continued to play, some are now professional musicians despite not attending conservatory. The schools they tend to go to are:
U of Michigan
U of Massachusetts
Northeastern
Northwestern
Tufts
Brown
Harvard
Columbia
NYU
New School
Reed
Oberlin
University of Rochester
McGill
Emerson
Wheaton in Norton MA
Clark University
Wesleyan