What we commonly understand today by the notion of theme comes to us essentially from the 20th century, in the sense that themes are not only at the origin of musical discourse and its development, but are also bearers of meaning: symbolic, anecdotal, dramatic, metaphysical, what have you? Nevertheless, even within this generally accepted concept of theme, there are major discrepancies as to its formal insertion in the elaboration of the work.

While pure music has, in a way, marked the triumph of the subordination of the various formal components to the overall structure, everything that has interfered with the strictly musical substance - especially theater (opera, ballet) or poetry - has given rise to the emancipation of the formal framework from the thematic. In this sense, influences from outside music have helped the composer to free himself from a pre-established trajectory, from the very visible constraints of literal return and repetition, and to find a notion of form that has more recourse to the instant and to insubordination. But what would give coherence to the musical discourse: of course, the notion of theme.

As the concept of form evolves, so must the notion of theme, for there is an absolute interaction between the way in which the theme is organized and multiplied, and its use to animate the formal framework to be invented; all the more so as these two notions are linked by the evolution of language itself. So, as language moves beyond its traditional framework, the notion of theme plays a key role, expanding in two opposite directions, creating a conflict of choices and options, but also of uses and manipulations.

The dilemma is as follows: hyperthematism in relationships at the lowest level, infrathematism at the highest. How does it work? The theme will be both hypertheme and infratheme. Hypertheme: all figures will be deduced directly from the intervals of a given primordial figure, and only from those intervals. Infratheme: this given primordial figure will have from a theme only the characteristic of intervals; neither rhythms nor durations, still less sequences and associations. On such an absolute, taking so little account of musical reality , its material and its capacity for development, we couldn't stay long.

Two observations are essential to overcome this fundamental contradiction:

  • the theme is an essentially malleable material, ranging from the most explicit characterization to a reduction to amorphous components, losing the advantages of its own profile for the benefit of a ductility that allows infinitely more extensive use: a permanent state of variability that will result in the work being inscribed in a universe in perpetual evolution.
  • the overall organization cannot allow the components of language to develop in a state of mutual ignorance and passivity: the divergence of extreme rationality and free intuition creates, at best, a conflict, at worst, an incoherence detrimental to the overall grasp.

In rather naively contradictory terms, we can hope to confront thematism and athematism: an opposition which, in less crude terms, seems to me fundamental to the very idea of development. Identity and variation: this is the inevitable encounter that invention must propose. Identity not real, but virtual; identity in principle of a family of musical objects conceived according to the same type of derivation, the same model of description. Thematic components are no longer extracted from a given object, the theme, by detaching certain of its properties; they are expressed as principles and can only be perceived through the various "materializations" they are able to perform. Apart from these thematic matrices, the evidence of composition is also based on the notions of signals and envelopes, the signals being of a punctual order, the envelopes of a global character. If matrices determine figures and serve to "type" them, signals serve to mark the articulation points of a development, of a form. A signal is, in a way, a reduction of the theme to a stronger element that absorbs all the others. Envelopes, on the other hand, mark the prevalence, for a given beat, of one thematic dimension over the others; this thematic element may be of a very precise order: interval, duration, or other quantitative parameter, but it may also be of a very general order, such as register, speed, dynamics, timbre, or even type of writing, continuity, directionality - in other words, parameters, or rather criteria, that are essentially qualitative.

The theme, the thematic entity, cannot be conceived solely as precise figures attached to given intervals or rhythms, but must be understood as more generalizable phenomena. The thematic entity ultimately unifies the composer's multiple approaches, from his choice of material to his decisions on form. Musical perception and expression have thus been enriched by a new domain that we are only just beginning to explore.

P. B.