Conversation so far:
When did Jeanette MacDonald start musical theatre?
In November 1919, Jeanette MacDonald joined her older sister Blossom in New York and landed a job in the chorus of Ned Wayburn's The Demi-Tasse Revue.

Question: What did she do in the theatre?
Self-contained rewrite: What did Jeanette MacDonald do in the theatre?