Fillmore East 1971 is one of my favorite Zappa/Mothers albums. I love the whole "storyline" with the guys in the band trying to pick up the groupies. It's actually based on a true story, too.
Mark Volman and Howard Kaylan, a.k.a. "The Phlorescent Leech & Eddie" a.k.a. "Flo & Eddie" were the lead singers of the 60's band The Turtles, who were known for such hits as "Happy Together". They joined The Mothers after The Turtles broke up. After a Mothers show one time, Flo and Eddie were trying to pick up these girls who had been at the show, but they weren't impressed, as it wasn't really their kind of music. They were more into songs like you'd hear on the radio. Flo and Eddie said "Hey, we were in The Turtles. You know the song Happy Together? We sang that." But the girls wouldn't believe them unless they actually sang the song for them. So they did, and everyone got laid that night. True story. I love rock and roll.