Muhlenberg may be worth looking at as more of a safey.
Lafayette has a frat culture similar to Lehigh’s so if he wants to stay away from schools with a noticeable Greek presence he may want to take Lafayette off his list.
BTW, the Greek percentages at some schools are skewed by the fact that students aren’t allowed to join until sophomore year. IOW, at a school where 33% of students are in frats 44% of those sophomores-seniors eligible to join are Greek.
@Sue22 I was wondering about that for Lafayette. Oh, well.
@happy1 Muhlenberg has come up in conversation. Maybe …
I’d also kick the tires at F&M re: greek life as I think it is over 30% there.
Additionally, even schools without greek life can lean a little bro-y and the social practices of athletic teams can replace the greek life feel on campus. Middlebury comes to mind for me in that regard although I’m sure opinions vary.
I think he has the stats to be a reasonable candidate for his reaches, but they are reaches so they reject many highly qualified kids.
Would Oberlin be too left-leaning for him?
If 21% fraternity participation at SUNY Geneseo is problematic, 22% at Franklin and Marshall and 23% at Lafayette may be also. There are unrecognized off-campus fraternities at Brandeis, but there seem to be no stats on what percentage of male students participate in them.
According to this link, the percentage at F&M is much higher - 35%
https://www.fandm.edu/campus-life/get-involved/fraternity-and-sorority-life
@HCPP20 While there is Greek life on campus at University of Rochester and a fair proportion of students are involved, it’s a very laid-back version of Greek life. Sororities don’t have houses but members may live on dedicated dorm floors. Same for a number of the fraternities. My daughter was fairly anti-Greek when she went to college but joined a sorority and has had a good experience. It doesn’t define the college experience there the way it does at some schools. Instead, a sorority or fraternity is usually just one of many organizations that someone may belong to. My daughter is close to the girls in her sorority but also has friends (including her boyfriend of two years) who aren’t involved in Greek life.
Kenyon. A low-key place; definitely worth the drive to check it out.
Muhlenberg. https://www.muhlenberg.edu/hillel/
University of Pittsburgh
http://www.hillel.org/college-guide/list/record/university-of-pittsburgh
According to Lafayette’s Greek page
Another possibility if he’s willing to travel outside the NE would be St. Olaf. Lots of music, but again Midwest so I don’t know how many Jewish fellow students he’d have. Probably a match on paper but could be more of a likely because he’s from outside their region.
https://wp.stolaf.edu/music/
https://www.stolaf.edu/orgs/list/index.cfm?fuseaction=orginfo&OrgID=441¤taction=listallorgs
@brantly. I didn’t catch your Jewish comment. Yes, Holy Cross is a Jesuit college and as such is welcoming to ALL faiths or NO faith. No religious pressure on anyone. We are not Catholic and are incredibly impressed with Holy Cross.
Muhlenberg has a very big Jewish population, and I think would work well with his love of music as well. Small, nice merit and I think it would be a match, possibly a safety.
Ugh. Thanks. So hard to find the right one. And you’re right, @doschicos about the sports-team culture replacing frat culture. I think that might be the case at Amherst.
My kids were looking for a similar vibe as your son and had good luck finding it at midwestern LACs. If there’s a way he’d consider that region, I think it would be a lot easier to build a balanced list. 
My D recently graduated from Lafayette. While Greek Life is certainly present on campus one can absolutely have a full and happy social life without participating. (If the OP has any questions about Lafayette that a parent can answer feel free to PM me).
I think Amherst has a very ‘bro’ culture. It had fraternities until just a few years ago and they were so wild they had to get rid of them. For a year or two there were still fraternities off campus, and they had to get rid of those. I don’t think the culture can change so quickly.
I love the school, but I don’t think they are bro-less.
I’d look at Carleton and the Midwestern schools (Grinnell, Macalister). St. Olaf’s has a great music program but is religious.
1984: Amherst no longer allows fraternities/sororities as recognized or on-campus entities, but they could remain as off-campus organizations.
2014: Amherst prohibits students from joining fraternities/sororities.
I 2nd Muhlenberg
Also look into Clark