Evolution of the opening measured vibrato in An Idyll for the Misbegotten
Rhythmic integrity is crucial in learning George Crumb's music. While it is gestural in nature, each rhythmic motive should be approached accurately and with intension.
To demonstrate the importance of Crumb's rhythmic detail, you will see the evolution of the opening flute line in An Idyll for the Misbegotten.
The opening triplet figure stays the same throughout each sketch, however the rhythm of the measured vibrato is worth noting.
In Figure 1, notice how it is marked "slow vibrato." It is clear that Crumb has the measured vibrato technique in mind, but it has not solidified into the precise, palindromic rhythm that appears in the published score.
Figure 2 represents the change from slow vibrato to the first appearance of measured rhythm. However, notice key clicks represent the device for performing this rhythm, not vibrato. Also, the first half of the palindrome is present here - with groupings of 3, 4, and 5 pulsations.
Figure 3 shows the transition from key clicks to instructed measured vibrato. The rhythmic value stays consistent with the previous example, but now there is the appearance of pitch bending following the measured vibrato passage.
In Figure 4, you'll notice the placement of the pitch bending now proceeds the measured vibrato. In addition, Crumb adds key clicks to emphasize the difference rhythmically between the bending pitches and measured vibrato.
Regarding the measured vibrato in Figure 5, you'll notice the completion of the rhythmic palindrome, with the addition of the duple group in the beginning of the figure. This creates asymmetry. Also, Crumb removes the pitch bending figure that proceeds the measured vibrato.
Figure 6 shows the edits seen in Figure 5. Crumb has removed the pitch bends in figure 5. This sketch is the finalized intension and precision that Crumb was deriving in this small rhythmic cell.
Figure 7 is taken from the published score. You'll notice the integration of articulation markings under the measured vibrato. This is meant to emphasize this rhythmic figure.
These sketches show the evolution of one small, rhythmic idea. It is easy for performers to not be fully aware of the lengthy process the composer has for each musical idea. By watching the evolution of this small, rhythmic cell, it will hopefully inspire the flutist to understand Crumb's process with all rhythms throughout his works, and also view this same treatment to all musical elements.