In VibraZoyd (2012) for vibraphone and electronics –dedicated to Gérard Hourbette and Monique Vialadieu, a 2012 commission from Art-Zoyd: Centre Transfrontalier de Production et de Création Musicales, with Robin Meier as RIM (Réalisateur de Informatique Musical – Computer Music Designer)– I have sought to explore the labyrinths of time and to make the traditional wave paradigm of recent centuries coexist along with the more contemporary granular paradigm, close to the universe of particles (protons, neutrons, neutrinos…), micro-movements and energies.

The particular feature of this score is in the exploitation of bow techniques, carried to the extreme, applied to the vibraphone bars with two or four bows, two mallets and two bows simultaneously, or a bow with glissando mallet. The result is a sound very like that of sine waves.

My aim in VibraZoyd is to fuse electronic and instrumental sounds, so that they become indistinguishable. Fundamental to the score (apart from the F of 174.61 Hertz –Hz– the lowest on the instrument) is the use of “differential sounds”, pulses that appear when two or more frequencies that are very close together are superimposed; a pulsation emerges from this superposition, sometimes perceptible as rhythm, sometimes as a modification of the timbre of the two frequencies when added to them. These sounds do not in fact exist: our brain constructs them by trying to differentiate one frequency from the other; for example, when an A of 440 Hz is superimposed on another A of 446 Hz, our perception will hear, in addition to those two notes, a virtual rhythm of 6 pulsations per second; by superimposing an E of 1318.51 Hz and an F of 1396.9 Hz (the highest note on the vibraphone) a frequency of 78.4 Hz is obtained which, imperceptible as rhythm because of the speed of the pulsation, is integrated as timbre, modifying the colour of the E and the F. In the work’s first and last sections, each note or notes played by the vibraphone in combination with its “doubles” produced by the electronics generates diverse differential rhythms, from one to seventeen pulses per second. These rhythms sometimes provide reference for metric modulations and changes of overall tempo, and sometimes build polyphonic fabrics that transform constantly, shifting away, approaching, and moving around the listener, placing both the real space (the performer and the hall’s acoustics) and the virtual space reproduced by the nine loudspeakers surrounding the public (in the 3D version) at different points, to make it easier to hear the dense polyphony of pitches and rhythms. This happens in the bars where the performer plays with four bows to produce four pitches which, combined with their twins in the electronics, give four different differential rhythms that are super-imposed, sustained and combined with the same treatment in successive bars but with divergent differential rhythms on each occasion.

Later, the interrelation between frequencies expands thanks to FM (Frequency Modulation), AM (Amplitude Modulation) and RM (Ring Modulation), synthesis models whereby the vibraphone sounds are modulated by the electronic sounds, creating colours characteristic of electronic synthesis. A feature of this section is that the synthesis models are fed back depending on the vibraphone’s intensity of attack, giving the electronic material a live character, generating timbres which are characteristic but which change with each performance, because the electronics’ parameters never vary while the intensities, always relative, variable and peculiar to the percussionist performing the work, do.

As already pointed out, both harmonically and formally, the work is based on the instrument’s lowest note, a 174.61 Hz F, the fundamental of a hypothetical spectrum of both harmonics and times which depend on this note and its associated partials; it is successively transposed down- wards and this generates a slow pulsation, so slow that it is perceived as form rather than as rhythm or pitch. Exactly the same thing happens with the remaining harmonics of this F which, depending on their place in the register, take on multiple functions such as pitch, form, duration, tempo or timbre.

In the central part of the work, I have developed a flexible treatment of time, but which is extremely precisely controlled so that the pulsation is diluted as it follows an organic flow that expands and compresses microscopically, like a spider’s web that retains its structure but varies without losing its tension. This is a granular treatment, where thousands of sound particles interweave, compress and expand.

Lasting 17 minutes, the work is impregnated with a mystical and evocative nature, comparable to a multi-sided crystal that fragments the light in an infinity of celestial reflections. With sound, these reflections are converted into waves and instrumental and electronic textures that surround and hypnotise us: a sonic sculpture in movement, transporting us into an infinite, unearthly space. VibraZoyd was premiered by Miquel Bernat at the Cervantes Institute in Paris on 23 January 2013.

José Manuel López López