Conversation so far:
What did he do with the Rolling Stones?
Taylor's onstage debut as a Rolling Stone, at the age of 20.
What year was that?
1969.
How long did he play with the Stones?
CANNOTANSWER.

Question: What else happened during this time?
Self-contained rewrite: Besides Mick Taylor's debut with the Rolling Stones, what else happened during 1969?