John Mayall appeared with Delbert McClinton and Glen Clark at the Orpheum Theater on November 13, 1972.

Dan Rheaume says:

I was at that show! I had never heard of Delbert & Glen before. Delbert came out and grabbed a mic as Glen sat down at a Wurlitzer electric piano. Delbert said, “Hey! I’m Delbert and this is Glen and we’re going to have a really good time!” Then they proceeded to blow the roof offa da joint. Then John Mayall capped off the night with a full cover of Jazz/Blues Fusion!!!

Delbert McClinton had famously played the harmonica on Bruce Channel’s hit song “Hey Baby” in 1962.