The most significant element which is under the control of the composer is time. By controlling the way the listener perceives time, a well written musical composition garners the full attention of the listener to the point that there is no awareness of time passing. Real time, therefore is converted into relative time, the time of the piece, and provides the framework for a unified emotional response from the listener. Regardless of the style of the piece, historical time in which it was written, or format (instrumental forces, text, etc.) all compositions will interact with human nature and the common perceptual mechnisms through the measurement of time.
The task of the composer, then, is to create expectation and involvement on the part of the listener that is so poised that confusion from too many ideas or boredom do not set in. How is this balance accomplished? There is a relationship between size of a musical idea (theme, subject, tune, etc.) and the size of each musical phrase; and, in turn the size of phrases and the period of phrase groups. Beyond that, the structure of a section will reflect the size of the periods. Each part of a musical idea is like the fragment of a sculpture: contained within it are the keys to overall proportion. If I unearth the index finger of an ancient statue, I will be able to guess its approximate size. In a representational universe with human scale, the analogy is obvious; in the abstract world of music the perception of relative size is more challenging and requires some technique.
Although music students study the structure of pieces by predetermined categories, such as sonata, ABA, rondo, etc., no composer, even one in the generation of Haydn or Mozart, would select a structure willy nilly independent of the basic pitch material. Looking at any theme (term here is used extremely loosely) some pitches will be longer, louder, in an opposed register, with a contrasting articulation (attack), to distinguish them from others. Consequently, these pitches (or sounds) will generate an automatic foreground, while in the hierarchy other groups of pitches or sounds will have lesser roles. In a static environment the state of affairs is easily comprehensible; however, in the dynamic playfield of a musical work, the roles of the pitches are constantly being altered. So, a small accompanimental motif could rise to the foreground, while primary material recedes. First ideas are not necessarily the most important: In Beethoven's Fifth Symphony, Movement I, the opening motif immediately earns our attention by its preeminence; by contrast the opening of Debussy's La Mer is barely understandable in its lack of focus, because the primary ideas come later in the movement.
The key to compositional technique on the local level is the independent control of all the parameters affecting the theme: the pitches (as pitch classes ie. all G's, as opposed to a single G) themselves, their duration (including repetitions), articulation, dynamic level and their recurrence in groups (motivic contours). With regard to rhythm there are a number of factors: 1) the rhythm of a given line, 2) the composite rhythm of two or more lines (which may be delineated by register), and 3) the harmonic rhythm of the event itself. The first two factors generate a phenomenon I call pitch density, the number of attacks per unit time. If pitch density increases, then there is the illusion of more activity, excitement, information. The third factor generates a perception of how many pitches constitute a single event. The opening of Stravinsky's Petrouchka contains an undulating wind figure that has close pitch density and much activity, but it describes a single harmonic event and becomes static as a backdrop to the short melodic excursions above and below it. It is both fast and slow at the same time.
The ability of the skilled composer to control these dynamic factors of fast and slow music is the key to the control of the listener's emotional response. It is akin to the film editor, who uses fast cuts to build tension and slow pans to create repose. I am sure that there are a few music students reading this article and wondering: None of this sounds like any of the stuff my theory teachers taught me. What about roots, triads, counterpoint, and all the other constructs? Remember, a music student analyzes a piece that is complete and firmly ensconced in past tradition. The garnered umbrella concepts help to categorize style periods. My approach to the discussion assumes the piece is BEING WRITTEN and that all decisions are up for grabs. This is the essential difference between what composers do and what theorists observe.
Independent, dynamic, polydimensional decisions over time are the work of the composer and the primary reason for the innate complexity of developmental music composition. A long piece cannot be written without this web of interdependent decisions. Luckily the composer has a time machine and can spend weeks, months, or even years, pondering them. Also the dynamic environment can be reduced to a series of simpler, static decisions.
This little article just begins to scratch the surface of what is meant by Compositional Technique, but I hope it will go a long way to uncovering the mystery of the composer's art for any listener.