I took my first crack at writing micropolyphonic music in the sixth (and perhaps my favorite) ouroboros miniature, Swell. It’s a cool little piece for guitar duet in which various chords played as very rapid ad-lib arpeggios begin pianissimo and slowly swell to forte, before returning to pianissimo, at which point the figure repeats itself with a slight harmonic change. As one guitar does this, the other performs a similar gesture out of phase (as in, one is playing very quietly getting louder while the other is playing loudly getting quieter). The result is a pretty cool texture on both the micro and middle levels. The very fast arpeggios tend to go in and out of phase, creating interesting rapid rhythms that change drastically with every performance. The duration of the swells also has a certain level of indeterminacy, similar to the rapid ad-lib arpeggiation (but slightly more controlled) that create a unique, somewhat irregular harmonic rhythm that slowly morphs and transforms over time. The key to this piece is the rapid arpeggios, though – it acts as a sort of sustain for the harmony and allows the performer to control the dynamics really well.
I recently got the idea of doing a similar piece (perhaps rewriting the same one, if I’m lazy) for the guitar orchestra in la Casa de los Tres Mundos, Granada. Rather than two guitarists each doing three-note arpeggios, you can have six guitarists each doing rapid tremolo on a single note. It might be best to use a plectrum with some rapid alternate picking, since the classical or flamenco tremolo technique tends to be rather quiet, and we rehearse outside with all of the city’s traffic noises and other music students drowning out our guitars. Start with the one-note tremolo, then add some arpeggios to increase the harmonic density and even throw in some rasgueado abanicos to do rapid six-note chords. Methinks ‘twould be a good study for those particular guitar techniques, and it would also introduce the students to reading music notation with a certain level of indeterminacy (ad-lib rhythms and durations denoted in approximate seconds).