Stage director Robert Wilson achieved worldwide fame for the striking originality of his avant-garde productions. What we learn from Katharina Otto-Bernstein’s terrific new documentary Absolute Wilson was that the great director’s art was simply imitating life. Growing up in Waco, Texas—his father was that city’s colorful and conservative mayor—Wilson stuttered until a ballet teacher named Byrd Hoffman recommended he slow down his conversations. He took that advice to heart and it cured his stuttering. It also laid the groundwork for a revolutionary theatrical language, a style that often saw stage action unfold at a glacial pace. The documentary includes extensive interviews with the usually reticent Wilson, along with shorter discussions with the director’s colleagues and contemporaries—composer Philip Glass (with whom Wilson created his signature work Einstein on the Beach), writer Susan Sontag, and critic John Rockwell, among others. But the real value of this film is its treasure trove of archival footage, rare clips that document this genius of an artist as a young man.