Bruno Serrou: In the next piece you chose, you use Upic. It's Nocturne, which you composed in April 1981.

François-Bernard Mâche: The idea here was to explore a type of writing that I'll be using again in other pieces, and which I define as contour canons. By canon, I mean that a single melodic line will superimpose itself polyphonically, and by contour, I mean that it's not quite the same melodic line but the same melodic outline, an important dimension that has almost never been exploited as such by a composer. Yet it's enough to refer to the visual metaphor to realize that a line can take on related but different forms, depending, for example, on whether it is amplified or inverted. The idea of contours or inflection points in a melodic line can be consciously employed, giving rise to continuous variations. This structural feature of the work is accompanied by another feature stemming from the fact that I have combined a number of melodic contours derived from Upic's synthesized sounds, with other sounds made at the same time on the piano. The piano often intervenes in unison with the synthesized sounds, creating a hybridization of timbres. The work is very difficult for the pianist to play. As certain contours cannot be reduced to a given pulse, I had to write the vertical projection of superimposed lines. So the pianist has to play a lot of very difficult things in a tempo imposed by the tape, which he has to learn by heart if he plays with it. 

Bruno Serrou: Is the tape an accessory?

François-Bernard Mâche: I also allow solo piano performance, but the tape completely changes the sound and adds parts that the piano doesn't pick up. With solo piano, we lose the effects of timbre and polyphony, but gain in flexibility of interpretation.

François-Bernard Mâche, De la musique, des langues et des oiseaux, Michel de Maule -INA 2007, p.263-264