Conversation so far:
What did James Levine do with the Opera?
During Levine's tenure, the Metropolitan Opera orchestra expanded its activities into the realms of recording, and separate concert series for the orchestra.
Was he a singer or writer?
he was named principal conductor of the Metropolitan Opera in February 1972.

Question: How long did he work with them?
Self-contained rewrite: How long did James Levine work with Metropolitan Opera?