Karl Stockhausen's intriguing Helicopter String Quartet is a complex piece of music. Here it is interpreted by the Digital Music Ensemble at the University of Michigan:

A bigger version for those with a faster broadband connection. The Digital Music Ensemble's interpretation of the piece uses model helicopters instead of full-scale ones, a quartet of electric guitarists in place of a string quartet, and a live video processing dimension.

Stockhausen's work explodes the concept of traditional music and this is first and last string quartet. Although it is performable as a self-sufficient piece, it also forms the third scene of the opera Mittwoch aus Licht ("Wednesday from Licht") which is part of the Licht opera project, which consists of 7 operas.

This real helicopter version of the Helicopter String Quartet is described thus:

A string quartet is presented to the audience, before leaving for the four helicopters waiting outside. The helicopter blades begin to turn, and take off; each containing a string player. A sophisticated system of video and sound equipment transmits the performance back to a mixing desk in the hall for the audience, via a multichannel sound system with the 4 performers made visible on video monitors, The quartet are seen to be playing completely synchronously as they make their ascent. The sounds of the helicopters are mixed with the string quartet for the listeners as the helicopters fly above the city. The three melodies of Licht are heard as sharply accented notes rotated from one player to the next, during the constant glissandi. The tremolando style of playing blends with the noise of the helicopter blades. Finally a slow descent brings the musicians back to earth, and they re-enter the concert-hall for the applause.

It's a fascinating idea. I doubt if it will ever be staged in its entirety in Australia.