Tool #3: Octave Displacement

I am fascinated by motivic development.  The idea of a small seed sprouting into a gigantic tree is intriguing to me (in the figuratively musical sense), because it is an origin that keeps relating to itself, an organic microcosm, a universe born of one or a small few simple ideas.

I was lucky to have composition teachers who shared this interest, and as early as my freshman year at Hartt I was given a list of ways that one can develop an idea (not every way conceivable in the universe, but still a very comprehensive list).  Although I have since misplaced that list, I often think of it when I have my “seed” that I want to grow into the gigantic tree.  Some of the ways of transforming ideas that it covered were rhythmic alteration (augmentation, diminution, etc.), transposition, inversion, retrograde, fragmentation, expansion, and many others.

I hope that I will be able to write a “Tool” on this blog for each way of developing an idea, so I decided to start with a rather simple one: octave displacement.

Octave displacement can take on various forms.  One way of using octave displacement is transposition of the entire idea up an octave.  This is very common in many jazz tunes–Pat Metheny is a master of this.  Transposing the whole melody or motive up an octave can add variety, excitement, and a sense of direction, all while keeping the material organic.

Another method of using octave displacment is raising certain pitches by an octave.  If I have the melody C#4-D4-A3-G3, I can change the pitches by an octave to create a new contour and make “melodic accents” (as I term them): notes that inherently jump out of the melody without necessarily needing accent articulation markings.  If I make the A3 into A4 (raising it up an octave), the gap between A4 and G3 accentuates the A4 a little and the G3 a lot, because one is used to hearing a P4 descent from D to A, but now one hears a P5 leap up followed by a M9 leap down.  If I raise the C#4 to C#5, I have created a M7 descending, and this has a jarring effect when juxtaposed with the m2 step upwards that one hears in the beginning of the original phrase.

I highly suggest that you try this out–it works great on melodies and motives, and can add variety and intrigue while recycling material.  There are all sorts of ways one can displace octaves in a phrase, from the entire phrase, to groups of notes in the phrase, to certain pitch classes, rhythmic classes, or just single notes–the list goes on and on.

Questions?  Comments?

Thanks for reading!


2 thoughts on “Tool #3: Octave Displacement

  1. Such a wonderful endorsement of a one of our simplest techniques, yet one with perhaps the most potential for good results! Aren’t there psychoacoustic phenomena at play here? The idea of “tracking,” the idea that groups of pitches separated by large registral space are heard as different melodic ideas, would make an interesting follow-up!

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