We came across this Sit and Play orchestra as we were walking to see the play at the National Theatre. In a nut shell, every cube is a different musical instrument. i.e. every cube represents an instrument in an orchestra. As you approach the "orchestra" you hear a very well known classical composition (mozart, handel ir vivaldi) and you can just stand there and enjoy the magic. However, if you were to desire to join in and make a contribution all you had to do is sit on one of the cubes and "play". You can actually hear the instrument beneath you adding to the overall beauty. You can see me sitting on a Viola :)