Spend some time figuring out some strong matches that your kid would be happy to attend. We can come up with lot’s of reaches but the trickier thing I think are to find schools likely to be accepted at that your kid will be happy with. Within the UC system, UCSC might be a great candidate as a match because for a UC, their music department is pretty strong and they have a pretty extensive world music commitment and their math/computation programs are also solid. Someone mentioned Utah above, and I agree it could be a great option their music school seems significant and they are fairly strong in math/computation. CalPoly is another good potential match, although I have no idea what the music program is like there. It is somewhat unique there in terms of match vs reach because you are competing for slots in a particular major, so it really depends how popular the major is you are applying for. Another match to look at is potentially University of Rochester (NY) the academics are solid there, and Eastman is top notch for music, they might have a dual BA program. The winter weather there will be a change from CA though. Another reach to consider is Northwestern.