Little Big Mouth Ending Explained [SPOILER!]

SPOILER ALERT: the following article contains massive spoilers, including the ending. If you have not yet seen the movie, proceed at your own risk, or better, come back to this article later!

SPOILERS AHEAD

Little Big Mouth Plot Summary and Synopsis

Kicked out of his band and home, a playful guitarist takes refuge with a bookkeeper, her son and dad. Is it possible to make sweet music together?

Source: Wikipedia (CC BY-SA 3.0).