I've been gigging regularly since the 1960's and can think of only one player (my current sax man) who survives solely playing live music. He does supplement somewhat teaching private lessons after school hours. Other than that, he works with me when needed and with others, as well. I, along with everyone else I've known musically, had a regular day job. Most of those I work with now are retired, so gigging is a monetary supplement and simply fun. Our gigs are similar to what others have already stated. Residing in a university town is a big assist, since there's always a lot going on, with opportunities to play.

Don't do it if your first priority is making money.

The best part is not the money, but sleeping late every day.