How heartening it is to know that Ken Loach is still out there making committed, polemical cinema, so long as you don't have to watch it. Never go near a Ken Loach film unless you're trying to sleep with a socialist. If you are, however, Land And Freedom should do the trick.
If you got up on the bandstand at Minton's and couldn't play, you were not only going to be embarrassed by the people ignoring you or booing you, you might get your ass kicked.