Iannis Xenakis: Music for Keyboard Instruments - realized by computer

COMPLEXITY - UNPLAYABILITY - TRUE TO THE ORIGINAL
IANNIS XENAKIS' COMPOSITIONS FOR SOLO PIANO AND SOLO HARPSICHORD
REALIZED ON THE COMPUTER

In the music of Iannis Xenakis, rationality and emotionality are inextricably linked. The structures of his basically emotional pieces should be understood as codes of human existence. For the performers of his music, this means trying to play the 'notes' as faithfully as possible. On the other hand, none of the compositions presented here can really be reproduced 'correctly'. What's more, they are sometimes unplayable because in all the pieces Xenakis very often ignores or exceeds the technical possibilities of the respective instrument.

He prescribes sound effects that cannot be achieved with the help of the piano or the harpsichord, such as the ever-present tremolo in demisemiquavers in the harpsichord piece Khoaï or the much too rapid repetition of notes in the piano piece Evryali. Even short single tones cannot be realized if the damper pedal on the piano is pressed at the same time, as required in Herma. The main reason for the difficulty in playing the compositions correctly, however, is that they sometimes exhibit a complexity and intricacy that no interpreter can cope with in reality. To clarify this aspect, some features of the pieces are briefly described.

The large heaps of notes are typical of Xenakis' music. They are sometimes formed relatively simply, for example from a large number of stochastically (i.e. aleatorically or statistically) assembled tones. Xenakis called such chaotic clay masses 'clay swarms' or 'clay clouds'. In the case of a tone cloud like here in Herma (minute 6:27 to 6:37 of this recording), the performer only has to correctly reproduce its tonal range and density – i.e. the number of individual tones per second – which is not a major problem.

It becomes very difficult when large groups of tones are created very precisely, for example by interweaving short melodic or rhythmic units repeated in different pitches. Such passages can be heard on this CD in the pieces Mists (0:00–1:05) and Khoaï (4:48–5:04): here very chromatic ascending or descending tonal ›lines‹ are interleaved. A similar situation is formed by the canon-like superimposition and/or interpenetration of often repeated and similarly rhythmic individual tones, which can be heard in Evryali (0:52–1:04) or in Khoaï (3:11–3:30), among others.

In Naama even three different rhythms are superimposed (4:14-4:35). Understandably, these complicated sound textures, formed by repetition, layering and interweaving, cannot be faithfully reproduced rhythmically by a single musician, just as he could not realize correct part-writing.
It becomes even more complicated for an interpreter when the many lines or voices of a sound fabric cross each other, as in Evryali (2:33–2:59): voice crossings on the piano can only be explained to a very limited extent because of the uniform timbre of this instrument.

The only option left to the pianist is to differentiate between the different voices via the volume, which, however, only comes close to the intended effect to a limited extent. On the harpsichord, voice crossings on a single manual, as Xenakis prescribes in the piece Naama (13:13–13:36), cannot be made audible at all. Another obstacle for the performer is the simultaneous playback of two differently structured ›sound clouds‹ or textures, either layered or interpenetrating. An example of such a situation can be heard in Herma (1:07–1:40): Here a layer of staccato notes and a layer whose tones should form a compact sound cloud with the help of the pedal should be played simultaneously. Actually, such and similar passages should be played by two pianists on two pianos.

It is natural to wonder why Xenakis nevertheless composed such complex pieces for a solo instrument and not for several pianos or harpsichords or for an instrumental ensemble. Or why he didn't immediately realize it on the computer as 'electronic' or 'electro-acoustic' music, in which there are neither human nor instrumental limitations and where the sound result and artistic intention correspond completely. In the case of the present compositions, he may have wanted the music to be controlled uniformly or centrally, which implies a solo piece and thus a single interpreter.

One could also assume that he conceived some of the pieces for a piano, because a lot of them are also very 'pianistic'. As an example, see the ascending arpeggios at the beginning of Mists (0:00–1:05). These and similar passages call for a piano sound. An additional reason may have something to do with a problem with the reception of electro-acoustic music: In a public concert – i.e. in a unique communicative situation – a composition that is recorded in the recording studio and subsequently played back on audio carriers is taken very differently and perhaps less intensively true as music performed directly. In the case of the pieces discussed here, Xenakis may have preferred imperfect but 'lively' performance in order to establish better contact with the audience.

The desire to hear the compositions as Xenakis probably imagined them and notated them very precisely is, of course, nevertheless justified. With this CD, the conductor Daniel Grossmann is probably the first to present an attempt to reconstruct the composer's tonal ideas. The very spontaneous-looking recordings are actually the result of intensive work on the computer. A lot of fine tuning was necessary, especially in the area of ​​the volume ratio of individual tones.

The rhythmic sequence of the individual tones in dense, aleatoric clouds of tone, which Xenakis deliberately notated rhythmically imprecisely, such as in Mists (3:15–6:30), always had to be considered. Creating the tonal balance within precisely structured textures, as well as the optimal volume ratio between superimposed but differently structured layers, was an important part of Grossmann's work.

In addition, with the help of careful panning, ie the acoustic distribution of different tones and groups of tones on the right and left loudspeakers, he has made the individuality and autonomy of the different sound levels evident. In certain cases, he made the basic pulse and tempo given by the computer so irregular that it was hardly noticeably irregular, thereby 'humanizing' it. An important goal of his work was not least the development of a convincing dramaturgy for the individual compositions, i.e. the optimal ratio of loud and quiet parts as well as the most appropriate length of the crescendi and decrescendi.

Paradoxically, it is precisely this (computer) recording, which was created so rationally, that allows the great liveliness and freshness of Xenakis' music to fully appear. Since the CD is not (primarily) intended for playback in public concerts, the problem of the reception of electronic music described above does not apply in this case. The recordings should be judged like any normal recording, namely as documentation of a musical act of interpretation with its own artistic claim. Nevertheless, the present CD is of course not intended as a substitute for existing or future “real” recordings of the pieces. However, she would like to facilitate the reception of the compositions by both the audience and the instrumentalists.

tom sora