Here’s another post on (one of) my obsessions: motivic development.  So far I’ve talked about octave displacement and additive processes in this motivic development vein, so I’d like to add another tool to the list of ways to develop motivically: Augmentation/Diminution.

This is a pretty simple technique.  It assumes that there is melodic or harmonic material whose rhythms can be expanded and contracted.  Augmentation is simply the lengthening or rhythmic values, and diminution is the shortening of rhythmic values.

For example, if you have the phrase (in B Locrian, just for kicks):




You can apply augmentation evenly to expand it to:



Or you can apply diminution evenly to diminish it to:




You can apply mixed augmentation:



Mixed diminution:



Or a combination of both!



How you use augmentation and diminution depends on the musical situation.  If you want to increase tension, you might use diminution to make things go faster and seem more hurriedly, whereas if you want a broader resolution, you might consider augmenting the melody that has been a main theme when you arrive at a recapitulation.  But, the core of the idea is that it serves to develop the musical ideas and move the piece forward.  Your uses might be completely different from someone else’s, but may achieve a similar result.

Questions?  Comments?  Feel free to leave a comment/note if you’d like!