While at the Warsaw Autumn I was reminded of a lot of compositional ideas that I had not thought about actively in quite some time, some as back as far as when I was first seriously starting to compose in college. One observation that was particularly influential for me was in considering harmonic and inharmonic sounds and how that works on higher scales of time (or levels of form). In thinking about inharmonic and harmonic sounds, I found that they are really not so different, just that with harmonic sounds the fundamental frequency is audibly present, while with inharmonic sounds the fundamental frequency is audibly missing.
For the frequencies given in an inharmonic sound, one normally states them as being a fundamental with non-whole number or irrational multipliers to show the relationship of other frequencies present. However, one can see them in a different light as a sound where the fundamental isn’t present.
Let’s say a sound is broken down into frequencies 500, 700, 1300. This can be stated as a fundamental of 500 and then harmonics at 1.399 and 2.6 times the fundamental: a common way to state the present frequencies when working with additive synthesis. However, to look at it as a sound with the fundamental frequency missing, one can state it as the 5th, 7th, and 13th partial above a missing 100 hertz fundamental.
With a harmonic sound, the period in which the content of the sound repeats is audibly present and is the duration of one cycle of the fundamental. If one considers all of the frequencies each as an identifiable pattern, then the total pattern will repeat itself every period of the fundamental, regardless of phase of frequency.
However, for the inharmonic sound, the period in which the content of the sound repeats is not present and will always be a duration longer than any of the periods present in the audible frequencies. In the inharmonic example above, the pattern of the frequencies repeats every period in the 100 hertz missing signal.
This way of looking at sounds greatly affected my way of working with music on all levels of time. In my listening experience, I found that harmonic sounds naturally spoke more quickly than inharmonic sounds. I found that with sounds like bells or gongs, that the natural thing when hitting them was to let them ring and have a long decay, and that it would take longer for my ear to adjust to really hear the sound of the bell than it did for harmonic sounds.
Taking this observation and applying it to higher levels of musical time structures, I found that harmonies which were complex were dissonant when held short amounts of time but became softer in quality (more consonant) when they were present for a longer amount of time.
On a different level which I’ve been most involved with, for complex time relationships and layers of time to speak, I found that using simpler material and at slower rates allowed establishment of different temporal layers to occur, while not giving ideas enough time for the layer of time to speak would result in the composed layers to bind together into a single layer perceptually.
The observation on harmonic and inharmonic sounds has long held an impression on me and continues to affect my own way of working with music today. This observation has not lead to the formulation of hard rules to music, but rather has acted as one of a number of guiding impressions for me when composing music. (Afterall, rules derive from taste, do they not?)