Bruno Serrou: Shortly after Prélude, you composed Volumes, a work that was premiered a year later and in which you already made use of the mix. 

François-Bernard Mâche: This characteristic set me apart from my colleagues in the GRM, who had the utopian idea that electroacoustic music was going to replace acoustics because it was much more general and made it possible to control all the parameters of sound, since it escaped the vagaries of interpretation. I never adhered to this programme, believing that electroacoustic music should aim to be no more than an adjunct or an alloy, with instrumental writing retaining all its power. In Volumes, I made a lot of use of recorded instruments, in particular harpsichords. But electroacoustics offered me the possibility of doing things that would be impossible to do live, for example, an orchestra of ten harpsichords, thirty-six bassoons and so on. I recorded all the notes of rare instruments such as the contrabass saxophone. I brought a harpsichord into the studio to record it, while I improvised on it. In this way I was able to manipulate sound materials from the acoustic world, which I couldn't access live. 

Bruno Serrou: How did you come to think of the harpsichord in 1960, an instrument that was neglected at the time? Why not the viola da gamba?

 François-Bernard Mâche: In fact, I was attracted to the harpsichord long before that. As early as 1953, four years before the Duo, the first piece I recognised, I wrote a page for harpsichord, a sort of toccata. Following this experience of the harpsichord used in the Volumes tape, this interest grew considerably, the amplification transforming the harpsichord into an instrument of unheard-of violence. It was this brutality that attracted me and that I wanted to exploit.

 Bruno Serrou: A bit in the spirit of Ligeti's Continuum, which focuses on the mechanical aspect of the harpsichord?

 Francois Bernard Mâche: What's fascinating about Continuum is that Ligeti manages to get a continuous sound paste out of an instrument that produces distinct, dry notes through velocity alone, which is astonishing. There's already a bit of this in the swarming harpsichord sounds recorded in my Volumes. But above all I was working towards a kind of percussion instrument with an assertive violence. This is what we find later in Korwar, for example. Coming back to Volumes, in addition to the original instrumental recordings, I used seven live trombones, an apocalyptic instrument par excellence, which was reinforced by the symbolism of the number 7. I also used instruments that I had experimented with at the GRM, such as the string plate. This was a steel sheet suspended by strings of the same metal that could be played either as a struck percussion instrument or as an instrument in which the sheet acted as a resonator for the plucked steel string. I never used this instrument again, even though it produced some interesting sounds. So there was this slightly adventurous side... and there was also the piano. This piece also has the distinction of being the only concert in which I took part as a performer. Constantin Simonović was on the podium in a concert at the Théâtre de Poche in Paris, and I was playing the piano.

 Bruno Serrou: Did the use of seven slide trombones encourage you to use micro-intervals?

 François-Bernard Mâche: I only use this type of writing when I have to. It has never been a specific area of research for me. When I need a finer scale than the semitone, I use the quarter-tone, just as Ohana used the third-tone. In Andromède, I sometimes went as far as the eighth-tone, for the low string instruments, in order to obtain certain timbres that were inaccessible to me.
to obtain certain timbres that are inaccessible by dividing the chromatic scale alone. I only consider the micro-interval in the context of research into colours.

 Bruno Serrou: Does the fact that you put an 's' in Volumes mean that you consider this term in your work in its full sense? 

François-Bernard Mâche: Especially in the sense given to it by Koechlin in his magnificent Traité d'Orchestration, where he notes a quality of timbre expressed by the word volume that is not confused with brilliance or richness, and which means that a sound occupies an imaginary space, whatever the real volume it takes up in the hall. Koechlin writes, for example: "The low tones of the flute are voluminous, but they are easily pierced. This metaphor of a sound's own volume, of the imaginary space it occupies, was of particular interest to me, because it gives sounds a sculptural aspect, with dense, closed, punctual, piercing, etc. sounds. The 's' in the title is explained by the fact that I don't use just one kind of volume, but also because the sounds develop in space through the swarming multiplicity of polyphony. I recorded bisbigliandi of very rapid notes on the harpsichord, and multiplied the instrument by manipulations that allowed me to obtain a surreal abundance.

François-Bernard Mâche, De la musique, des langues et des oiseaux, Michel de Maule -INA 2007, p.226-229