Wow, Twink....what a cool memory with ZZ Top.
I was just a teen at the time. We knew they were playing at the Spectrum that night and the Manager was a fan too.
It was just the Manager and me closing that night, they came through drive thru first, Manager was in the office and I was finishing up closing/cleaning. At first I was “nope, don’t think so” then they came to the front doors and I called the Manager, who was a fan, and we were both all we have to let them in, lol. She made me promise not to rat her out to the owners. We turned on the broiler and fryer (whoppers, fries and onion rings) per their request.
They were the nicest people ever. And gave us a $100 tip, and back then that was mindblowing to me.