"The Book of Mormon" is, in my view, a great musical, but most of the score is forgettable -- it's the book, lyrics, and performances that make the show. I won't quickly forget the translation of "Hasa Diga Eboway" or the line, "I have maggots in my scrotum," but the music itself, for me, is NOT the key to the show.
While not a "great" show, "Something Rotten" is terrific -- but once again, it's the clever premise, the humor, the wordplay, the dancing, and the satire that make it terrific. The music is forgettable, except that it consists largely of songs that would violate copyright except that the music parodies the originals.
Audrey, the Phantom Phanatic, who nonetheless would rather be Jean Valjean, who knew how to make lemonade out of lemons.