One of the reasons the 17-movement work is so rarely performed, despite Zappa’s celebrity, is the fiendishly tricky rhythm in some spots. (You know how triplets are three-notes-in-two? One spot has 23-notes-in-18.) And then there are the movement titles, which range from “Outrage at Valdez” (about the Exxon oil-tanker spill) and “Food Gathering in Post-Industrial America 1992” to “Dog Breath Variations” and “The Girl in the Magnesium Dress.”