<p>This is probably what you’re looking for at CMU: [BXA</a> Intercollege Degree Programs - BSA Program](<a href=“BSA Program - BXA Intercollege Degree Programs - Carnegie Mellon University”>BSA Program - BXA Intercollege Degree Programs - Carnegie Mellon University)</p>
<p>It is an interdisciplinary program between the CFA and another school. She could do music and math there, would have an advisor in both departments. Probably not easy to get into (I think you have to be accepted into both schools), and no doubt challenging, but it’s not unusual and it is structured so you can finish in four years.</p>