There's bandleaders who have geared their entire performance so if you can pick this kind of thing up by ear, follow their timing, and put effort into making them sound better, you're more valuable than some alternatives having truly advanced formal musical training.

Especially with equal or better chops, lots of players like this can go into a studio and make recordable music, in one take, without actually rehearsing together in advance.

And play in any key, since it's just Roman numerals.