Very few LAC’s (going by the strict definition) offer “significant” musical theatre programs. Many with excellent acting programs do not offer coursework in MT nor do they stage musicals.
The only top 100 LAC with an MT program that I know of is #72 Illinois Wesleyan (BFA MT). Muhlenberg (#65) does not have an MT program but they do have a large theatre program that regularly stages musicals.
Top 100 National Universities with MT programs include (pretty sure these are “very academically focused universities,” but your mileage may vary):
12 Northwestern (MT cert)
23 USC (MT Minor)
24 UCLA
24 Carnegie Mellon
27 Michigan
32 William and Mary (MT courses)
36 NYU
39 BU (MT minor)
39 Northeastern (MT minor)
39 Tulane
39 UCI
44 Miami
50 Penn State
50 Pepperdine (BA in Music and Theatre)
50 Florida
56 SMU (MT Minor, does not stage musicals)
60 Syracuse
68 BYU
70 Rutgers (starting in 2019)
71 Baylor
74 American
82 Michigan State (MT minor)
82 TCU
82 Iowa (Music/Theatre double major)
86 Indiana
86 Tulsa
92 Florida State
92 Colorado
99 Auburn
Top 10 Regional Universities with MT programs include:
6 Ithaca
8 Emerson
1 Elon
4 Samford
6 Belmont
8 James Madison
2 Santa Clara (MT minor)
1 Creighton
3 Drake
I scanned down the lists rapidly, so I hope I didn’t miss any, but I may have.
Rankings listed are from US News.