Allusion is, unlike intertextuality, deliberate, and, unlike plagiarism, meant to be recognized. It presumes “a community of knowledge,” a phrase I like for its fellow feeling.

Review: A Tharp Master Class on Themes, Variations and Allusions A program celebrating Twyla Tharp’s 60th year making dances features the masterwork “Diabelli” and the fresh new “Slacktide ...