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.

Question: who else did Mike work with?
Self-contained rewrite: Besides playing piano on Moby Grape's 1968 Grape Jam, who else did Mike work with?