The Drowsy Chaperone is an homage to American musicals of the Jazz Age, examining the effect musicals have on the fans who adore them.

The Man in Chair, a mousy, agoraphobic Broadway fanatic, seeking to cure his "non-specific sadness", listens to a recording of a fictional 1928 musical comedy, The Drowsy Chaperone. As he listens to this rare recording, he is transported into the musical. The characters appear in his dingy apartment, and it is transformed into an impressive Broadway set with seashell footlights, sparkling furniture, painted backdrops, and glitzy costumes.