The main character of a musical finally sings and breaks the audiences heart

Not sure if this one is allowed but I'll try it

Hint 1: loosely based on a classic movie

Hint 2: starts off as a comedy and gets darker as it goes on

Hint 3: the singing for the first time happens at the end of the show

Hint 4: technically not a "movie" in the traditional sense but it is feature length

Hint 5: expanding on the previous hint it's a proshot of a play which is why I wasn't sure if it's allowed