One of the measures of greatness is how much an artist influences those who come after him. By that measure Alvin Ailey has ensured his place in dance history: he’s “spawned at least five major companies built in the Ailey image — Philadanco, Dallas Black Dance Theatre, Cleo Parker Robinson Dance Ensemble in Denver, Lula Washington Dance Theatre in Los Angeles and Dayton Contemporary Dance Company — and many small groups, inspired by Ailey’s success.”