I went to a "Yes" concert in Savannah Ga around 1974, I was doing quaaludes or something.
Don't remember a thing about the concert, but afterward we went to a Burger King.
The sign was dancing for me (I was too out of it at first to go inside, so I sat in the car for a while)
When I went in and got in line (after concert munchies, the line was LONG) which was inching forward.
I caught sight of myself in the windows, it seemed my irises were spinning or something, it was so fascinating.
Suddenly people were laughing, and I realized the line had moved up about 10 ft while I stood there.
Maybe it was Mescaline