Conversation so far:
When did James Levine join the opera?
James Levine made his Metropolitan Opera (the Met) debut at age 28 on June 5, 1971.
what was James Levine doing in the opera?
James Levine became the Met's principal conductor in 1973, and its music director in 1975.
Did James Levine do anything else for the Metropolitan Opera besides conducting and directing music?
James Levine became the company's first artistic director in 1986.

Question: what was he known for?
Self-contained rewrite: what was James Levine known for?