I went to that JGB show. It was supposed to be a couple nights earlier and got postponed, to the same night as Zappa at Jones Beach. I sold my Zappa ticket to see JGB even though I had never seen Zappa live. I ended up seeing Zappa once.
Good Skates Roller Rink transformed in a short lived music venue, it was packed and very hot and uncomfortable. JGB played a hell of a show.