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Zebra Finches perch on an electric guitar on July 8, 2009 in a aviary in Nantes as part of a creation by French Celeste Boursier-Mougenot named “From Here to Ear.” The project features 40 zebra finches, let loose in a space rigged with hanging harpsichord strings and coat hangers ,all connected to an audio system. As the audience enters the space, the birds move and perch on different structures triggering unique ambient sound patterns. Aleatoric music is that which leaves an element to chance as Celeste Boursier-Mougenot has here.
John Cage is perhaps the best known composer of such music. Early in his career he added objects (such as screws, seen below) to piano strings to create an unpredictable rattle or damping of sound as the instrument was played. As he delved deeper into chance operations he used elements of randomness by incorporating radio broadcasts into performances and using the ancient Chinese text, I Ching, to guide the cutting and rearrangement of a piece recorded on tape into a pastiche.