Conversation so far:
what work did Mike Bloomfield do with Al Kooper?
Bloomfield and Kooper had played piano on Moby Grape's 1968 Grape Jam.
how long did they work together?
CANNOTANSWER.
who else did Mike work with?
Dylan's.
what other careers or hobbies did mike do/have in his life?
CANNOTANSWER.

Question: all they did was play piano together? (mike and al)?
Self-contained rewrite: All Mike Bloomfield and Al Kooper did together was play piano?