1. The Beginning of the Journey

Ideally, every path towards the performance of a work moves in small, meticulous steps that help the conductor prepare the right ground (historical, analytical and technical) in which to begin cultivating his or her own sonic idea of the piece he or she is going to perform [1]. In the case of Les Espaces Acoustiques, as Nathalie Hérold has pointed out in her text “Une approche des Espaces acoustiques de Grisey par une documentation de l'acte musical: quelques pistes d'analyse” [2] a series of articles of an analytical nature, as well as texts which are more oriented towards the discussion of aesthetic issues, as well as numerous written testimonies by the composer himself, can serve as a first point of orientation. In Pierre-André Valade's case, this phase has – for biographical and chronological reasons – happily coincided with the founding of the ensemble Court Circuit in 1991 and the subsequent opportunity to collaborate with Grisey himself in the preparation of the performance of Périodes and Partiels, which were recorded on the CD Accord label between 1997 and 1998 [3], and enabled him to proceed with awareness and understanding in the preparation of the performance of Modulations, Transitoires and Épilogue, which were first directed by Valade only after Grisey's death in Vienna in 2000 (2:18-3:00) [4].

Traces of the collaboration for the 1996 performance are still to be found in the form of notes copied on the page with the Périodes ensemble indication (Figure 1) and dated 14 April 1996. They contain a number of observations concerning performance technique, intonation, character of gestures and reminders of difficult passages. These comments already allow us to introduce a first distinction of the different categories of annotations that a conductor may decide to introduce in his material including:

1. Dynamic balance (dynamic (and timbral) balance between instruments (foreground/background or as will be seen later);
2. Extended techniques: various annotations on extended technique specifications as a vehicle for the particular timbral-morphological results required;
3. Bow technique: as a vehicle for rhythmic articulation (irregular or regular) or timbral results (pay attention to the indication on the bridge);
4. Construction of complex (inharmonic) sounds: precision of the pizzicato or accentuation as part of a morphologically more complex events or the nature of the 'scratch' as a vehicle of inharmonic quality.

However, these kinds of annotations are already the result of the relationship with an ensemble and with the composer; as such, they therefore belong to an advanced phase, following the one concerning the studying and reading of the score, a phase to which may belong quite different kinds of signs developed in the abstract (in the absence of the physical sound) or on the basis of exposure to recordings [5]. Les Espaces Acoustiques is a work whose performance reception boasts a discrete persistence in the programming of concert seasons and festivals throughout the world [6]. The conductor approaching the study of the cycle is thus faced with a choice: since he/she also has several recordings of both the complete cycle [7] and its individual pieces [8], the choice of whether to work with the recordings or tackle the reading of the score at the desk (or piano). This is a matter of personal method. Certainly, in the construction of the sound image of this type of music, the memorisation of the timbral quality of the vertical aggregates (harmonic or inharmonic spectra) is a meticulous and difficult task to construct with an equally tempered instrument such as the piano. The role of the inner ear, exercised through the experience of performing similar pieces, can prove to be of decisive importance so that the mental image with which one arrives in front of the orchestra is as sharp as possible. There are some aesthetic reasons that I think it is important to emphasize.

The first reason lies in the very nature of spectral music, which is based on the concept of instrumental synthesis, a concept that presupposes that by means of a specific distribution of pitches in the acoustic space and careful intonation of each (partial) harmonic component, it is possible to merge, on a perceptual level, the intervallic relationships between the components into a higher timbral quality. [9] Whether the writing is static (with sustained notes, as at the beginning of Périodes and Partiels) or articulated through figures and gestures (as in Prologue, and section D of Modulations, etc.), correct intonation is primordial for the realisation of the phenomenon of sound fusion. As will be seen later, many moments of the rehearsals both in separate sections and, all the more so with the orchestra united, will be devoted to the refinement of intonation with the awareness that it is a vehicle for the correct construction of the musical sense of this particular type of compositional technique.