Conversation so far:
What is the Blood, Sweat & Tears' Jerry Fisher era?
Singer Clayton-Thomas left in early January 1972 and was replaced by Bobby Doyle and then Jerry Fisher, who went to front the next incarnation of Blood, Sweat & Tears.

Question: What was unique about this?
Self-contained rewrite: What was unique about the Blood, Sweat & Tears' Jerry Fisher era?