Pithoprakta premiered in 1968, when even Balanchine—middle-aged and Old World—must have recognized that America was cracking open. The sexy corps of this 10-minute ballet amasses and separates in mysterious submission to a wild, urgent score by Iannis Xenakis that a lay listener cannot anticipate from one moment to the next. The principal woman and man (originally, the supreme Suzanne Farrell and Arthur Mitchell) shadow each other but never touch. The critics were intrigued, but a year later, when Mitchell left to start the Dance Theatre of Harlem and Balanchine’s possessiveness drove away the young Farrell, the choreographer let Pithoprakta go. After a resounding success staging another rarity made for her, the gypsy cosplay Tzigane (renamed Errante for our more enlightened era ), Farrell brings the strange piece back home. Completing the All-Balanchine program are three earlier works, on regular rotation at the New York City Ballet: the gothic one-acter La Sonnambula; the hauntingly elusive The Unanswered Question, set to the eponymous Ives (an intriguing complement to Xenakis); and Theme and Variations, which returns us with a jolt to neoclassical speed and sparkle. —Apollinaire Scherr