In addition to what’s been noted…
Amherst College is part of the Five College Consortium (with Hampshire College, Mount Holyoke College, Smith College and the University of Massachusetts); auditions at any of these schools are open to students within the consortium. There are other forms of collaboration too.
https://www.fivecolleges.edu/theater
Also, you may want to check out Wagner College, an under the radar liberal arts school that is very strong in musical theater.