Catharsis
Catharsis for two pianos, two percussionists, and electronics
Clearly indicated in the title, the musical project in this work is based on the concept of catharsis. In Greek, it means “separation of good with bad”. The term is used in medicine and psychoanalysis, but catharsis played a vital part in the ritual of antique theater as it “purified” the audience’s passions via a more “timely” vision of the concept of catharsis, rather than being the result of theater, it is one of its prerequisites: becoming detaches from one’s passions to better appreciate the performance. 
Didier Rotella applies the concept to the musical material directly, in the sense of the sublimation of this material: like a theme and variation—the composer references Beethoven’s Diabelli Variations—he makes a small figure, gesture, instrumental or electronic undergo a range of transformations. Mutating little by little, without ever presenting the same face to the audience, the figure imposes a unique listening on the audience. These variations—which are more variations in energy than in material—consist of a “detempering” of the pianos and percussive keyboards (marimba, vibraphone, glockenspiel et xylophone) – meaning the composer gradually moves away from the even tempering we know and the consequent harmonies towards an absolute abolition of pitch.
The other, essential, reference for Rotella is Karlheinz Stockhausen’s Kontakte. In this piece for piano, percussion, and electronics written between 1958 and 1960, the electronic tool is subject to a veritable manifest of the composer’s thought: an idea of a sonic and temporal continuum. According to him, the three essential parameters that define sound—pitch, length, and timbre—each reveal a different type of temporal perception. But, and this is the most important part, these three categories are not compartmentalized, they are intimately connected with each other. A sound impulse, sped up and repeated 440 times per second will also produce a la. If, instead of a single impulse, we consider that of a rhythmic cell that we speed up and repeat 440 times per second, we will again obtain a la, but a complex la, colored with a particular timbre, that depends on the rhythm chosen in the beginning. Inversely, by slowing down this rhythm, we enter the field of form and therefore of length. In Kontakte, Stockhausen ends the traditional distinction between harmony and melody, rhythm and meter, stature, phrasing and form, without mentioning timbre which we had only been concerned with up to this point as a note given for a specific instrument.
The electronics gather the percussive (or electronic) impulses on one hand and the pitches of the pianos and keyboards on the other in a federating movement that Didier Rotella hopes to reproduce here, this time using real-time processes and “augmented” instruments (instruments equipped with transductors that make it possible to transform the instruments into a loudspeaker with its own properties).
The Technological Issues
Catharsis does not use any revolutionary technological innovation. The work concentrates on refining and updating existing technologies, but also conjugating diverse tools to better serve the composer’s imagination.
The first focus of work was to perfect (or, rather, re-perfect because this type of tool already existed in the past) a system where a MIDI keyboard is set up in front of the real keyboard of a piano. It is important for Didier, himself a concert pianist, to create an important connection between the instrumental gesture and the writing for electronics: these new keyboards make it possible to modulate treatments in real-time depending on the musician’s touch…
Didier Rotella and Benjamin Lévy in studio at IRCAM © Déborah Lopatin
Second focus: augmenting the instruments. This concerns the pianos, but also the bass and snare drums. This “augmentation” enables an infinite array of interactions among these instruments: capture and re-introduction of sounds in each instrument, cross-captures of one instrument towards another, captures of percussions reinjected after transformation in the pianos, etc. The four musicians don’t only respond live through their performances, but also via the electronics… The augmented instruments also make it possible to diffuse prepared sound files, or to combine them with sounds made by the instruments during the performance. Among the sounds Dider reinjects are sounds produced using Modalys – a software program for sound synthesis via physical models. This software makes it possible, for example, to play a virtual string that’s 20 meters long and 5 millimeters thick, or a totally randomly pierced tube without having to make these objects. None the less, the sounds produced by Modalys are of little interest to Didier for whom they lack musicality. A large part of the work was therefore providing texture to these sounds by recompressing them (combining them with multiple sound sources, sampled from recordings of real instruments) and then modelling them in real-time depending on the musicians’ performance.
Biography
