Etudes Australes

Etudes Australes is a set of etudes for piano solo by John Cage, composed in 1974–75 for Grete Sultan. It comprises 32 indeterminate pieces written using star charts as source material. The etudes, conceived as duets for two independent hands, are extremely difficult to play. They were followed by two more collections of similarly difficult works: Freeman Etudes for violin (1977–90) and Etudes Boreales (1978) for cello and/or piano.

Cage wrote Etudes Australes for pianist and friend Grete Sultan, whom he had known since 1946. When Cage found out that Grete Sultan was working on his Music of Changes, a piece which involved hitting the piano with beaters and hands, he offered to write some new music for her, because to him "it didn't seem [right] that an aging lady should hit the piano" (Sultan turned 68 in 1974). Cage started working in January 1974 and finished the etudes in 1975.

The pieces are built on two basic ideas. The first is writing duets for independent hands, inspired by the way Sultan played. Cage made a catalogue of what triads, quatrads (four-note aggregates) and quintads (five-note aggregates) could be played by a single hand without the other assisting it; overall some 550 four- and five-note chords were available for each hand. The second idea was to use star charts as source material, as Cage had already done with the orchestral Atlas Eclipticalis in 1961 and with Song Books in 1970. This time Cage used the maps in Atlas Australis, an atlas of the southern sky by Antonín Bečvář, which he acquired in Prague in 1964.

The process of composition ran as follows. First, Cage put a transparent strip of about three-quarter inch over the maps. The width of the strip limited the number of stars used. Within this width Cage was able to discern the twelve tones of the octave. Then through chance operations using the I Ching, he transferred these tones to the available octaves for the left and right hands. The resulting notes reflect only the horizontal positions of the stars, and not all stars are used, because the maps used a variety of colors, and Cage's chance operations limited the choices every time to specific colors. In the end Cage would have a string of notes and ask the I Ching which of them are to remain single tones and which are to become parts of aggregates. In the first etude this question is answered by a single number, in the second by two numbers, etc. So as the etudes progress, there are more and more aggregates: in the first, most sounds are single tones, in the final, thirty-second etude, roughly half of the sounds are aggregates. The aggregates themselves were selected from the list of available aggregates, described above. Due to health problems, Cage himself was unable to prepare the manuscript; this was done for him by Carlo Carnevali (etudes I–VIII) and Wilmia Polnauer (etudes IX–XXXII).

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