My younger son has been playing in several bands that perform in humble (sometimes seedy, sleazy, or squalid) local clubs. These unheralded bands -- the music equivalent of catfish at the bottom of the great river of commercial entertainment -- hustle to get gigs as the opening act on an evening's program. The total pay is typically 50 dollars. For a quintet, this amounts to each band member receiving 10 bucks, enough money to cover gas and a burger at McDonald's.
To put these skimpy earnings in perspective, consider that a new set of strings for my son's violin costs 50 dollars. It makes one appreciate the irony that the word "gig" can refer to either a musical engagement or the spearing of a hapless fish.
Because a club pays by the performance, not by the number of players, the economics destabilize fledgling bands. A large band will tend to fission into duets and trios, which strike a more practical compromise between overall musical heft and the profit accruing to each player.