What kind of live art—performing art—belongs beside the 9/11 memorial pools, the engulfed pits, where the World Trade Center towers once rose? It is a daunting question, to which the first major dance commission at Lower Manhattan’s long-awaited Perelman Performing Arts Center answers: unison, a mode as ancient and ubiquitous as dance itself. The March is the brainchild of Annie-B Parson of New York City’s beloved, whip-smart Big Dance Theater, though she is probably best known for her choreography for David Byrne’s show American Utopia, in which she set the band marching while they sang. The March, however, features trained dancers and two additional choreographers, the fierce and brainy Donna Uchizono and the multi-hyphenate, multi-award-winning young Tendayi Kuumba, each for her own discrete part. “What happens when we dance together?” the choreographers ask. “And what happens when we don’t? How does unison deepen us? How has it been weaponized?” —Apollinaire Scherr