Justin Peck has lately become the go-to choreographer for Hollywood projects with classic pedigrees: Steven Spielberg’s West Side Story; Bradley Cooper’s artsy Leonard Bernstein biopic Maestro. But when it came to fashioning his own musical, Peck chose a different kind of classic: Illinois, the winsome, wistful, and weird 2005 album of Sufjan Stevens, the gay mystic indie star. Peck has been making dances to Stevens’s tunes—some found, others fashioned for him—for longer than he’s been New York City Ballet’s resident choreographer (a decade). But he’s been listening to Illinois—on repeat—even longer. The singer-songwriter’s break-out album takes poetic leaps between marching band brashness and plucky instrumentation, and sets the scenery of state history—state bird, state serial killer—against an imploding inner landscape. So Illinoise is not an obvious musical. Peck brought in a playwright—the Pulitzer-winner Jackie Sibblies Drury, no less—to help with the storytelling only to have her confirm that the lyrics and the choreography were script enough. An impressive stable of dancers and a live band of Sufjan regulars fill out the talent. After its sold-out run at the Park Avenue Armory, the show now comes to Broadway. —Apollinaire Scherr