While there are few horror musicals there are many musicals based on horror properties. You can change your monster to a clown or a hunk. It makes it easier to write a song for him, but doesn't guarantee a successful show.
NY Times on Young Frankenstein
No, it is not nearly as good as “The Producers,” Mr. Brooks’s previous Broadway musical. No, it is not as much fun as the 1974 Mel Brooks movie, also called “Young Frankenstein,” on which it is based….
Despite its fidelity to the film’s script, “The New Mel Brooks Musical Young Frankenstein” (to use its sprawling official title) feels less like a sustained book musical than an overblown burlesque revue, right down to its giggly smuttiness.
NY Times on Frankenstein a New Musical
For all their talk of fidelity to the original text, the show’s authors have departed radically from it in this piece of casting. … With hairless pecs and buzz cut, this Creature would probably be a man magnet on a Saturday night in Chelsea.
Village Voice on a third Frankenstein
While the first act follows the novel somewhat faithfully (excepting some scenes of haunting), the second contains some great departures, including a comic number the Creature (Timothy Warmen) sings to his unsuccessfully resurrected mate and a scene in which the Creature rapes Elizabeth (Cadden Jones) before throttling her. Perhaps rape scenes ought not be set to music at all, but if they are, they certainly should not include the repeated lyric "Forgive the intrusion."