THE ELECTRONIC WORKS OF GYÖRGY LIGETI AND THEIR ...

into filtered noise and shifting the register higher. In Apparitions, this process is
extremely gradual, taking the length of the entire movement, a duration of eight minutes;
in Pièce électronique no. 3, however, this happens very quickly, in a matter of seconds.
Thinking about form in terms of different layers defined by different dimensions
also elucidates one of the principle differences between Apparitions and Atmosphères.
After finishing the pieces where internal changes were contrasted with external ones,
Ligeti set out to compose a piece where the external influence was minimal. He describes
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Atmosphères as, “just a floating, fluctuating sound, although it is polyphonic.” The
emphasis here is on the singular–one sound, with the polyphonic elements relegated to
fluctuating internal dynamics. This is achieved in Atmosphères through a number of
means. The feeling of continual fluctuation occurs through instrumentation, most notably
the absence of percussion which played such an important role in the external events of
Apparitions. The musical surface of Atmosphères is also designed for continuity. Unlike
Apparitions, where some points on the ametrical grid were filled by silence, the surface of
Atmosphères is notably more continuous–rests are almost completely absent.
This continuity helps smooth over other divisions in the piece, such as the notable
shift in register which occurs at rehearsal letter G (3'51"), where the extremely high cluster
of the piccolos and violins is suddenly taken over by the ffff entrance of the contrabasses.
Even this division, which is clearly seen on the spectrograph (Figure 4.13), can be heard as
a type of transformation, as if the pitch-continuum were circular and the natural extension
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Ligeti in Conversation, 14.
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