The brilliance of Psycho does lie in the way that Hitchcock melds the obvious and the mysterious. He is outrageously obvious in his intentions; yet his artistry in camera angle and mise-en-scene make it possible to create a world that is rife with duality.
The late, great Stephen Sondheim had one request for tick, tick, BOOM! director Lin-Manuel Miranda: To record his own voicemail at the end of the film.
What you hear in this scene is Sondheim himself delivering his final message to Andrew Garfield's Jonathan Larson.