Those three Maine liberal arts colleges are excellent but not exactly in cities with good independent rock music scenes.
OP, you might be interested in the University of Georgia, which is in Athens. Athens is a small college town noted for it’s excellent independent music scene; there’s a long list of artists from multiple genres (mostly rock) who have come out of Athens, and there is actually [a Wikipedia page on the music of Athens](Music of Athens, Georgia - Wikipedia). Every summer they host AthFest - a nonprofit music and arts festival. Athens is also not far from Atlanta, which has a big music industry too. Lots of people will be into Georgia football, but lots won’t be - and it’s a above-average school that doesn’t have the reputation of being stressful. With your grades you would be eligible for their scholarships.
And since I mentioned Atlanta - Atlanta obviously has a thriving music scene in a variety of genres. There are tons of music festivals in Atlanta and lots of great nightclubs and small music venues. Much of the hype is centered around hip hop and R&B but Atlanta also has a pretty thriving indie rock community too. [Music of Atlanta](Music of Atlanta - Wikipedia) is also a Wiki page, lol. In Atlanta there’s of course Emory, but if that’s too stressful for you check out Oglethorpe University, a small liberal arts college (78% acceptance rate, but the students tend to score above-average on the SATs and from the top quarter to top half of their graduating classes). There’s also Georgia State University (more of a commuter campus btw) and a handful of smaller regional GA campuses that might be affordable for you.
Austin is another city noted for its music scene with South by Southwest and a bunch of other music festivals happening there, and the most live music venues of any city in the U.S. UT-Austin is of course the flagship there (and again - many students will be into football; many will not). There’s also St. Edward’s University, a medium-sized Catholic university; students there are also above-average but not amazing.
Nashville is another city noted for music - and not all country, either. Vanderbilt is an obvious option there, but there’s also Belmont University, a medium-sized average-ish university.
Seattle has a thriving musical culture, too - the home of 90s grunge (Nirvana, Soundgaden, Alice in Chains, Pearl Jam) but has a pretty diverse musical scene overall and has alt-rock and alt-music in general there too. Seattle has University of Washington, which may or may not offer some merit aid for you - but there are also the smaller schools like Seattle University and Seattle Pacific, both of which are middling/average type universities. Tacoma is also only about 40 minutes from Seattle, and the University of Puget Sound (a small LAC) is located there.
The Twin Cities apparently have a thriving music scene. University of Minnesota is there, but St. Olaf College and Macalester are relatively close by.
And of course there’s always New York and Los Angeles. In New York you have NYU and Columbia, but also Fordham, Marymount Manhattan, the CUNY colleges, Manhattan College, Pace, the New School, St. John’s and Yeshiva. In Los Angeles there’s USC, the Claremont Colleges, Occidental, Loyola Marymount, Azusa Pacific (evangelical), Loma Linda (Seventh Day Adventist), and Pepperdine.