I’m in a somewhat similar situation (I’m a pianist), though I don’t think I’m conservatory material, so I’ve been doing a lot of research into this!
Vassar and Wesleyan both have really strong departments. I don’t know as much about Swarthmore’s department, but I’ve heard it’s good. Amherst has a rather small department, but Smith, which is part of the same consortium, is very strong in music.
Bard’s music department in the college (distinct from the conservatory) is also very strong. It has plenty of its own teachers and resources, but you can still study with conservatory teachers and be in conservatory ensembles. At Oberlin I’ve heard things are a little more separate.
Lawrence University and St. Olaf College are frequently mentioned for students looking for liberal arts and music performance. They are lesser known than the other schools on your list, but they probably have the best music departments of any LACs. Lawrence has a conservatory, but it is very integrated with the college. Definitely check both of them out.
Some others with strong departments to look into are Williams, Pomona, Scripps if you are female, Sarah Lawrence, and Skidmore (which also has a music merit scholarship!)