Études australes is one of several large works Cage wrote during the 1970s by laying starmaps over manuscript paper and using the placement of the stars to determine the pitches. Cage used the I Ching to determine some of the other musical parameters but left the dynamic levels, attacks, and tempos to the discretion of the performer, and this has led to extraordinary diversity in the lengths of performances. The original recording by Grete Sultan, for whom Cage wrote the piece, lasts 169 minutes, Steffen Schleiermacher's version is 203 minutes, and the fastest, at 112 minutes, is by Claudio Crismani. That gives some perspective to the monumentality of this 2011 version by Sabine Liebner, which clocks in at 260 minutes.
A crucial performance element is Cage's direction, at the beginning of each movement, to depress a number of keys with rubber wedges so that their overtones will ring throughout the movement. Given the latitude Cage allowed his performers, it is difficult to determine what exactly constitutes a "good" performance as long as his instructions are followed, and the choice of a performance may simply come down to a listener's tastes. There are marked differences in interpretation that may cause listeners to prefer one version over another. Sultan's recording was the original interpretation, and that in itself carries some authority. The resonating strings are clearly audible and effectively impart a mysterious, astral aura to the music. The etudes are of varying length, lasting from four minutes to about seven, with most on the shorter side. In Crismani's recording the resonating strings are noticeably less audible. There are considerable differences in the lengths of his movements, ranging from just over a minute to six minutes, so his version has a lot of musical variety. Some etudes he plays with an almost metronomic pulse and they have a very pretty, sparkling quality, but this approach ignores the temporal irregularity that is implied by the spatial irregularity of the notes on the page. Liebner's version is anchored in her conviction that the spatial arrangement of the score must be reflected in the duration of the performance. She reasons that since the score for each etude is exactly the same -- eight lines of music over two pages -- and the distances on the star map have consistent values, the etudes should be of equal duration. Remarkably, each of her movements comes in at just about eight minutes. It's a smart and rational approach that very accurately reflects the details of what Cage wrote. Its drawback for some listeners may be that there is little differentiation between etudes. Other Cageians may have no trouble with this aspect of the performance. Liebner is exceptionally scrupulous about observing the relative durations and the pedaling Cage indicates. The resonating strings are not especially prominent, so the atmospheric overtones that feature prominently in Sultan's recording are often barely audible. Steffen Schleiermacher's version resembles Liebner's in its intense and focused musicality but because he is less strict about linking spatial relations to durations of each movement, his performance has more variety and differentiation. The sound of the piano in Liebner's four-disc set is clean but warm and the recording is realistic, spacious, and nicely ambient.