Conversation so far:
What is Leaving Basie?
Young left the Basie band in late 1940.
Why did he leave?
He is rumored to have refused to play with the band on Friday, December 13 of that year for superstitious reasons spurring his dismissal.
How did he react to his dismissal?
CANNOTANSWER.

Question: What did he do after he was dismissed?
Self-contained rewrite: What did Lester Young do after he was dismissed?