I knew I wanted to be a composer when I was in Junior High School. My parents found me a couple of teachers my last couple of years of high school. They were both well respected composers. The first teacher showed me Hindemith’s Theory of Interval Hierarchy on the first lesson. The second teacher waited until the second or third lesson, but then brought me a short treatise on Information Theory. Though I was totally baffled, these two events were actually a pretty good introduction to how many composers think about music.
Music composers and theorists have riddled music with a litany of systematic hierarchical structures. Tonality and key, harmony, meter and rhythm, form, and many more complex all-consuming theories are all systems of organized structures meant to impart logical meaning to emotional content. It is an idea borrowed from writing, and it is a visual concept. A large written work is organized into parts, chapters, sections, paragraphs, sentences, words, and finally letters. Each letter and word has its own function and meaning, and this becomes extended to sentences, paragraphs, etc., until every part has its own place and role. Most composers think of their music in the same way, with each note, phrase, or layer having a special function and meaning, and playing a part in a larger whole.
But it is impossible to retain this kind of detailed attention to multiple levels of musical structure while improvising. You can keep track of what is going on for a while but at a certain point you reach the Too Much Information point and things fall apart. With no pre-planning, the amount of information, levels, and functions add up until you are overwhelmed. At that point, you just give up and think about something else, because, after all, you are creating everything on the spot, not just the structure.
So when improvising, the amount of actual musical information you can pay attention to is limited. This is why many improvisers prefer to improvise on given themes or motives, because when doing that, the emphasis shifts to creative manipulation for which improvisation is excellent. But all of traditional musical theory treats music as information, so when freely improvising, you have three choices: 1) limit the amount of information you keep track of, 2) not care, or 3) keep track of your music in a different way. Choice No. 1 very quickly becomes a precondition. Limiting means making choices, usually in advance. This is how most of the world improvises, with limits of key or mode, tempo, meter, harmonic choices, etc. It narrows the playing field so that the improviser can concentrate on expression and creativity. Choice No. 2 pollutes the imagination and eventually becomes a choice. I believe that a lot of Free Jazz or Improvisation has become like this, where making an organizational choice of any sort becomes taboo.
It is not the music itself but its relationship to the surrounding music that gives it meaning.
I found that, as a composer, the only choice open to me was Choice No. 3 because I didn’t want to make pre-conditions and I did care. So instead of treating bits of music as information, I started treating them as relative values on the sliding scales of several simultaneous musical “fields” or parameters. Every bit of music I improvise is louder or softer, higher or lower, faster or slower, darker or lighter, more or less resonant, more or less dissonant, denser or more open, flatter or sharper, etc. than the music which is sounding simultaneously or adjacent to it. It is not the music itself but its relationship to the surrounding music that gives it meaning. Because emotion is perceived as a specific oscillation of intensity and release, and oscillation in many forms is a fundamental component of music, these relationships make excellent expressive tools while improvising. Most importantly, because their focus is very specific, they become tools that are actually possible to use while improvising in an intelligent way.
Because music has multiple dimensions, and these dimensions can be creatively manipulated simultaneously, the creative possibilities are nearly endless. An improviser can also create his or her own expressive parameters just by juxtaposition (i.e. more temple block and less triangle). Thinking about oscillating parameters encourages an improviser to concentrate on what he or she is doing at any given moment rather than creating the mental distance it takes to keep track of specific information over a longer period of time. This is exactly the mental attitude it takes to improvise well!
Of course, identifiable ideas do emerge. But instead of treating them as informational Legos to build things with, I treat those ideas as relational focal points that are altered and changed at every appearance. The information relates to itself. Large-scale structures do emerge too, but I don’t often think about them consciously. Sometimes I will deliberately bring back an idea from earlier within an improvisation if it is particularly prominent (and I remember it). Sometimes I will bring up an idea from a different improvisation or even another piece. But I seldom find that when I do it has any real or special impact. I find I can use and trust my musical instincts to control large-scale shape, contrast, and function. In other words, I play it by ear. It usually works. If it doesn’t, oh well, I’ll try again next time.