Analysis of a composition based on three sound gestures through spectral techniques
Updated: Jul 18, 2019
Visions in three planes: Cello, Ensemble and Live Electronics.
Composition by Gisela Paterno.
As the title suggests, the work is based on the idea of three different musical planes on which the work is built.
- The first generator plane or layer are three contrasting articulations on the note C2 (fourth Open string) of the violoncello.
- The second is a plane (or layer) that is based on different timbral processes on ideas displayed in the violoncello, so that the TAPE (Live Electronics) can offer a more microscopic view of the acoustic sound, fragmenting it into its spectral composition.
- The third and last plane is the result of the analysis of the harmonics of the sound of the violoncello, quantified to be interpreted by acoustic instruments through a free orchestration according to the presented ensemble:
Electric Guitar with a Pedalboard (Digitech RP-6)
The sound gesture exposed in these three planes was then complemented in its live performance with a video, giving a visual aid to what the music was expressing, the aim was to reinforce the sound gesture and translate it to a visual one.
Note: the Live Electronics are notated on the music sheet as well with specific symbols designed for this piece in particular in order to help the conductor following the changes on it.
INTRODUCTION (up to bar 17):
The introduction of this piece is based on four different sounds made on the tailpiece of the cello. The first sound is in the 2nd beat (B ¾ flat), then a D4 in the 2nd beat of the 5th beat, and the last two sounds are in the 12th and 14th bars (B flat 4)
The timbre varies in the position and the degree of pressure exerted on it. The sounds that make up this small first section of the work have as their purpose a sonority of indeterminate character, showing first the sonority of the cello with which it is least identified.
Over this layer, the cello makes certain sounds fixed in the score but in an improvised manner, always based on the sounds of the TAPE, which are also imitated by different instruments, such as the alto saxophone with sounds "with soffio" in bars 17 and 22, and the double bass and the violin with sounds on the bridge ("air") and Alto Sul Ponticello (ASP) in bar 22.
MOTIVE A (C Alto Sul Ponticello bar 18):
The sound used to give life to the first theme of the work is an articulation on the note C2 (fourth string to the air of the cello) executed from the position of Sul Tasto (SP) towards Alto Sul Ponticello (ASP) to then return to Sul Tasto , accompanied by a progressive increase in the dynamics when the bow reaches the Alto Sul Ponticello, and decreases when reaching again Sul Tasto.
The objective of sound manipulation on the 1st theme is to fragment this articulation in order to present it in layers. The sound is fragmented by frequency filters through a software called "Spear" that synthesizes the sound and executes an analysis called "sinusoidal partials analysis" that takes a "sampling rate" (sampling frequency) of 44,100 Hz. (Standard measurement for sample sounds or "Samples") and then performs a Fourier analysis (shown as "FFT size" in the analysis window of this software) showing the harmonics or overtones in the form of a sinusoid on the sound previously synthesized by the software.
Motive A is fragmented into four parts. Each part shows a specific area of the harmonics of the articulation of the cello, always taking the full sound and not an area which is “frozen” in time. For example, in bar 18 (image 1), the first harmonics marked by the red box (see figure 1) from 1100 to 3500 Hz appear in the second beat (see figure 2), followed immediately by the harmonics that are shown in grey (see graphic 3), these harmonic partials seen as sinusoidal sounds are cut in a specific way in time by tools offered by the software (Spear):
You can see an excerpt of the beginning of the piece to follow the music:
Here is a YouTube link to listen (and see the visuals that accompanied the piece performed live): https://www.youtube.com/watch?v=Usg_WnYUV7I&t=21s