In addition to Helicopter String Quartet, the opera includes an hour of electronic music and an a cappella choir singing in an artificial language created by the composer—he mentions the work in Scheffer's movie. In the film the music is performed by the Arditti Quartet, one of contemporary classical music's best and most adventurous ensembles. The four musicians perform the score in four separate airborne helicopters, and its pulsing rhythms blend in various ways with the thrumming din of each vehicle's rotors. The composer says the vision for the piece came to him in a dream, but as planning and rehearsal proceed he eventually admits that it's really about the technology that allows each performer to play in sync with the others and for the entire feed—sounds and video of the performers and the helicopters—to be mixed for an audience watching inside a dark auditorium. For much of his life Stockhausen was obsessed with spatial sound—placing different acoustic sources in different spaces to provide listeners with shifting, unusual sonic perspectives. In theory the Helicopter String Quartet would push this idea to its extreme, but as the film reveals, in reality it's a different story.
As Ben mentions in his post, it's fascinating to watch the crew troubleshoot as they prepare, and though the music is terrific, the piece is more about spectacle—doing something outlandish just to do it. For me the real heroes are the members of Arditti—violinists Irvine Arditti and Graeme Jennings, violist Garth Knox, and cellist Rohan de Saram—who navigate the incredibly difficult score with precision under absurdly difficult conditions (buffeted by noise, dazzled by sun, and cramped by the helicopters' small cabins). In the clip below, Stockhausen explains his initial inspiration for the work.
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