Joël-François Durand: Geister, wieder…
pour alto solo (2020)
World Premiere: Melia Watras, viola; May 4, 2023, Seattle, WA
Program Notes:
Geister,wieder… is a slightly modified version of the solo part of my work for viola and ensemble, Geister, schwebende Geisterwhich belongs to a group of works initiated in 2019, in which I explore the formal and structural potentials of an acoustic phenomenon known to all musicians when they tune their instruments: the beats that occur when two tones of very close frequencies are played at the same time. Geister, schwebende Geister is the first of the series; the second is a work for solo violin In a weightless quiet (2020), the third is my second string quartet Canto de amigo (2020) and the last to date, La descente de l’ange (2022) is for Bb clarinet and violin. In each of these works, the beats are generated by playing a note on one of the open strings of the instruments at the same time as a similar pitch with a microtonal deviation on another string, or with another instrument.
One thing I find fascinating in this use of controlled beat patterns is that they actually permit to directly experience what is usually considered a physical/mathematical concept. In sensory experience (auditory perception), we cannot be aware of the mathematical ratio between the frequencies of two notes played at the same time; it's an abstract concept (we don't hear a 3:2 ratio when we hear a fifth; we hear a fifth). But when the pitches are very close, the phenomenon of "first-order beat" becomes an actual experience. How this works is fairly simple to explain: if for example, the two frequencies are 3 Hz apart—say, 443 Hz and 440 Hz—we hear two things: first, the two original frequencies become one single tone (mathematically, it’s the median value of the two); additionally, we hear a pulsation of three beats animating this single tone. The “median value” in this case is 441.5 Hz; and the pulsation that accompanies it—the difference between the two original frequencies—is three beats per second which, when we hear them, is the audible manifestation of an arithmetic equation, in this case, the subtraction 443 - 440 = 3!
But above all this, I find fascinating how these beats have a sort of other-worldly character, appearing seemingly out of nowhere, since the rhythmic patterns they create are clearly audible, yet not directly produced by the performer, who is just playing the two pitches.
The form of Geister, wieder… is essentially sectional, where each section explores in turns the tonal regions of the three open strings of the viola G, D and A, and their extensions through microtones that generate 3, 5, 7 and 11 beats per second. After a long first section centered on A, the region of the G comes in dialog with that of the A. Further on, the region of the open string D is brought in contact with that of the G and in the more complex central section, all three regions enter in a polyphonic type of dialog. Later on, the return of the A brings the piece to a concluding section.
Geister, wieder… is dedicated to Melia Watras.