Six actors have memorized all the roles. YOU choose which part they'll play.
Such is the pitch sent to me by Folding Chair Classical Theatre, which I've included below. This could be interesting. I've been watching a bunch of improv lately, and it sounds to me like a similar sort of thing. "Ok, freeze! We're about to see the entrance of the King and Queen of the fairies. Who should play Oberon? You, sir, blue shirt in the third row, which of these actors should play Oberon?" Although that does make me want to add "And now give me a style of movie he should play it in, style of movie....anyone....film noir! I heard film noir. Ok, Oberon, you enter in the style of film noir." :)