Last time I was in Alpine Valley was maybe 1990 or 1991.
I also had tickets to a concert there on Aug 26th, 1990. I didn't go and have regretted it ever since. The show? Eric Clapton, Stevie Ray Vaughan and Robert Cray. It was a Sunday evening concert and I didn't go because I was being bucky with a chick I had been "dating" who owed me money and got me the tickets.
After that concert, SRV died in a helicopter crash.