Melody, song or lyric are terms that refer to a form of expression within a musical genre.
The genre is 'Musical'.
Theater in the form of musical drama is the genre of 'Wicked the Musical'. The genre of the book upon which the stage play is based is prose literature in the form of a novel. In the event of a film version, the genre most likely will be drama or musical drama.
Genre is another word for style. Musical genres range from plainchant to hip hop.