A large consensus of critics, dancers, and dance-loving audiences would agree that Twyla Tharp has succeeded in her mission. No one making serious dances in this country since the 1960s could ignore the challenge of her inventive, quirky, complex creations. No serious dance artist has ever stretched the boundaries between classical and popular, serious and silly, accessible and intellectual, as Twyla Tharp has. Even the arresting titles of her works convey their antic, inventive quality: The Bix Pieces, Deuce Coupe, Sue's Leg, Push Comes to Shove, Cutting Up. When she first began to...