When Angelin Preljocaj’s Helikopter had its New York premiere, in 2002, it was on a double bill with his Rite of Spring, as if to suggest that what Stravinsky’s discordant, unstoppable, and unprecedented score had been for the early–20th century, Stockhausen’s string quartet plus six helicopters’ worth of propellers would be for the early–21st. Even after the ghoulish megalomaniac composer wished out loud that he had been responsible for “the greatest work of art possible in the whole cosmos,” otherwise known as the World Trade Center attacks, this Cunningham-esque dance to the aeronautic assault of noise caught my breath and held it for the full half hour. Those were terrifying times. Remember how we couldn’t imagine a dumber President, more evil minions, or so much death and destruction dispatched so quickly? Preljocaj is feeling the exponentially amplified déjà vu, too, though he has not given in to despair. “Even though conservatism is boomeranging back on us,” he told an interviewer recently, “the outcome has, in no way, been decided.” The title of the program’s second piece, a premiere, is German for “light.” —Apollinaire Scherr