On today's date in 1976, an opera premiered at the Théatre Municipale in Avignon, France, that had very little in common with the operas of Mozart or Puccini. For starters, it ran for five hours with no breaks between acts. The audience was invited to wander in and out as it pleased. The libretto consisted of numbers, solfege syllables and some cryptic poems written by a neurologically impaired pupil from a New York School for Disturbed Children. Even the title of this new opera was unusual, suggesting something at once serious and surreal.

The opera in question was called "Einstein on the Beach." As part of the action on stage, a violinist dressed up like Albert Einstein wandered in and out of its surreal scenes, a reference to the fact that, in real life, the famous physicist was also a talented amateur violinist.

"Einstein on the Beach" was collaboration between two Americans: composer Philip Glass and set designer Robert Wilson. It made the rounds in Europe, attracted a great deal of attention, and came to America in November of 1976 for two sold-out performances in New York staged at the Metropolitan Opera by Glass and his ensemble.

"Einstein on the Beach" has been something of a cult classic ever since. Its music was even referenced as a kind of "in joke" during a popular TV commercial in which Einstein debates the merits of Coke vs. Pepsi. For the record, in the TV commercial, Albert chooses Pepsi.