I saw a then-mostly-unknown Soundgarden open for Canadian techno-thrashers Voivod at a tiny little club in Reseda, CA in 1990. Soundgarden tore the place up. Everyone was jumping up and down and going completely insane. Still one of the meanest, dirtiest, heaviest shows I've ever seen. And yeah....half the crowd left after their set. They'd be playing festivals and filling arenas about two years later.