Einstein on the Beach is an opera in four acts by Robert Wilson with music composed by Philip Glass. The opera eschews traditional narrative in favor of a formalist approach based on structured spaces laid out by Wilson in a series of storyboards which are framed and connected by five "knee plays" or intermezzos. The music was written "in the spring, summer and fall of 1975.""mostly in Cape Breton, Nova Scotia." Glass recounts the collaborative process: "I put [Wilson’s notebook of sketches] on the piano and composed each section like a portrait of the drawing before me. The score was begun in the spring of 1975 and completed by the following November, and those drawings were before me all the time."