The worst concert I ever attended was a Van Morrison concert. He was so drunk he was falling down, slurring, and was booed off the stage.
The only good thing at that concert was when Billy Preston got up from his organ to boogaloo across the stage, his enormous Afro wig fell off revealing a cue ball haircut beneath.
I saw Bob Dylan back in the 90's and I guarantee he was drunker than Morrison.