I was curious to know what shows actually aren't based on any source material, but are completely new: not based on a book, a play, a movie, or a jukebox musical.
'Lerner's story was based on a much older German story by Friedrich Gerstäcker about the mythical, German village of Germelshausen that fell under an evil, magic curse. In 1947, memories of the second World War were too fresh to present a German-themed musical on Broadway, so Lerner reimagined the story in Scotland, complete with tartan kilts, bonnie lassies, droning bagpipes, Highland flings and “Heather on the Hill”.'
Company is actually based on a series of short plays by George Furth. I'm not sure if they were ever preformed or published, but I know that was the starting point, then someone reccomended it be made into a musical with Stephen Sondheim.
I have several names, one is Julian2. I am also The Opps Girl. But cross me, and I become Bitch Dooku!
The Into the Woods characters are based on classic story book characters.
Dreamgirls is based on the Supremes is it not?
"I'm tellin' you, the only times I really feel the presence of God are when I'm having sex and during a great Broadway musical." - Nathan Lane - Jeffrey
Everything is "based" on something, but the question asked what musicals were not based on a book, a play, a movie, etc. Company started with Furth's unproduced plays, so I would argue that it is original. Sunday is a completely original story, as is Into the Woods. I would also classify musicals based on real-life events as original (Dreamgirls, Chorus Line, Caroline or Change).