Conversation so far:
How did Muddy Waters start his career?
In August 1941, Alan Lomax went to Stovall, Mississippi, on behalf of the Library of Congress to record various country blues musicians. Muddy Waters was one of those musicians.
What happened when Alan Lomax visited Muddy Waters?
Lomax brought Muddy Waters's stuff down and recorded me right in my house, and when he played back the first song I sounded just like anybody's records.“
Was Muddy Waters given a contract?
Eventually Muddy Waters was but not by Alan Lomax.
What year did Alan Lomax visit Muddy Waters?
Lomax visited Muddy Waters in August 1941.

Question: What did these performances in rowdy clubs lead to?
Self-contained rewrite: What did Muddy Waters performing in rowdy clubs lead to?