I'm sure this has been a thread before but was wondering if you've ever read a novel/memoir/whatever and thought damn, this'd be a great show! I remember after reading Toni Morrison's Beloved I could instantly see it staged and the technicalities of a haunted set design, maybe not necessarily a musical but the thought of a southern ghost story sung through spiritual is pretty powerful.
Nights at the Circus by Angela Carter. It could start out small as she starts describing her life from her dressing room, but then could expand as the events get wilder and more surreal. (Like Lady Day at Emerson's Bar and Grill transforming into Cabaret in form)
I recently finished reading Daisy Jones & The Six and spent much of the book thinking about what it would look like as a musical. I could see it being staged as if it were a bio-jukebox musical (a la Jersey Boys, Beautiful, etc.), albeit about a fictional band and with an original score. So long as they do a good job with the songs, I think it could actually be quite good.
I also was recently telling someone that I think The Great Gastby could make a great musical with the right team, and then came the announcement that Florence Welch has one in the works.
Some other novels I'd like to see on stage:
Sally Rooney's Normal People (with a score by Shaina Taub)
E.L. Konigsburg's From the Mixed-Up Files of Mrs. Basil E. Frankweiler (I actually think this could be a good potential project for Disney)
I'd love to see an adaptation of some of Bradbury's short stories into an anthology-style play or musical titled October Country. Similarly, Ted Chiang's short stories have a lot of promise. A musical of Arrival could be really interesting, particularly in playing with musical concepts like lietmotifs to communicate the concept of foreknowledge. The music could indicate something to the audience before the characters speak it, and it could structurally loop around back on itself.
Station Eleven could be really interesting with a director who could make it all work. I'd love to see some really inventive staging to clarify the two timelines.