Illinoise - a new kind of musical

or how to die in the play repeatedly

“Illinoise” in The Yard at Chicago Shakespeare, featuring original company members Gaby Diaz and Ben Cook. Photo: Matt Murphy

In every performance of “Illinoise,” the music of Sufjan Stevens choreographed by Justin Peck and storied with Jackie Sibblies Drury, the dancers Gaby Diaz and Ben Cook who are partnered in real life, dance to the song “Casimir …