THE ELECTRONIC WORKS OF GYÖRGY LIGETI AND THEIR ...

the descent of this material, which follows, and, indeed, extends the descent heard through
R Section F . On the other, the sine-tone counterpoint is now symmetrical, and this
ambiguous direction is a hallmark of this second stage. This transitional area is shown
below in Figure 2.20.
In the spectrograph, one can clearly see the axis of symmetry around, 5'39", but a
number of factors obscure the symmetry of these four sine-tone strands. One such factor
is the fact that the two-part counterpoint of the original Section D did not contain any
voice crossing, but when the lines are doubled with their retrogrades, both pairs cross
freely, making individual voices hard to follow. The symmetry of this area is also
disturbed by the use of filtering, which eliminates progressively more material as the
section goes on, and in particular from 5'45" onwards where only traces of the original
remain.
Invariant Passage (Reprise of Sections E and F)
The passage from 5'53" to 6'51" contains material from a variety of sections,
filtered into four separate events. Event 1, which runs from 5'53" to 6'01", contains
material from Section E; Event 2 (6'01-6'09") reveals material from Section C; Event 3
(6'09-6'26") uses excerpts from Sections B and E; and the final event (6'26-6'43") contains
material from Section F, and is followed by a long rest, as shown below in Figure 2.21.
While these events come from different sections, they all share a common trait,
emphasizing invariance. Event 1 consists of several of the invariant gestures found in
Section E. The familiar ring-modulated invariant gestures centered on 335, 3200 and
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