"Reverse Gravity" from "Hyperchromatica" for three retuned, computer-driven pianos by Kyle Gann (2016-17)
Program notes:
Reverse Gravity is a gnossienne in which - for the theoretical completeness of the set - relative heights within the overtone series are reversed. That is, the higher harmonics such as 7, 11, and 13 are most often heard in the bass, while the melodies above are in smaller-ratio scales on 1, 3, and 5. As a result, we get to hear scales like 12/11, 13/11, 14/11, 15/11, 16/11, and 14/13, 15/13, 16/13, 18/13, 20/13, and so on. In other words, where the Pavane used the harmonic series as a mode starting on the 5th harmonic, and Rings of Saturn used it as a mode starting on the 3rd, Reverse Gravity uses a number of different modes starting on the 7th, 11th, 13th, and others. The tame conventionality of the genre, Satie-inspired, sets off the weirdness of the universe of intervals we're not used to. Some will find it out-of-tune, but out-of-tuneness that is consistent and systematic I find exotic.
"Hyperchromatica" is a work in twenty-one movements, lasting three hours and 23 minutes, for three microtonally tuned Disklaviers (computer-driven pianos). The 13-limit just intonation tuning for the three pianos (Disklaviers), with 33 pitches per octave, is given at the bottom of this page. It would be more accurate, actually, to think of this not as music for three pianos, but for one piano with 243 keys. In addition to the microtonality, most of the pieces also use polytempo structures and other rhythmic difficulties that would make performance by human players impossible. The fusion of microtonality and polytempo that I began in Custer and Sitting Bull (1995-99) reaches a second climax here.
Orbits are repeating rhythmic events out of phase; the harmonic series is gravity in music - thus the astronomical theme points to the devices pervasive to the piece. Among the collection of movements a great disparity of styles will be noticed. This is deliberate and necessary. Had I only written abstract, austere pieces like Orbital Resonance and Liquid Mechanisms, some listeners would have said, "Well the tuning is interesting, but few people will be attracted to an idiom so peculiar." Had I written only tonal and melodic pieces like Pavane for a Dead Planet and Dark Forces Signify, some would have said, "Well he's not really doing anything new, just going back to old styles and retuning them exotically." In order to thoroughly explore this elegant tuning in a kind of Gradus ad Parnassum - in order to allow the tuning to make its full argument to an audience - I had to go both forward and backward in history, to show what we could have been doing these last few centuries had we not been limited to twelve pitches, and also to project into the future what music could become: and with the same 33 pitches. I had to create not a unified essay, but an alternate universe. Besides, I was like a kid in a candy store with all these new pitches, able to resurrect chord progressions from the past and make them sound otherworldly by restoring the minuscule discrepancies that equal temperament had swept under the carpet. Using the numbers 1, 3, 5, 7, 9, 11, 13, and 15 in the harmonic series, it was natural to emphasize the familiar 1-3-5 in one piece, and the strange 7-9-11 in another, and each has its revelations in this context. The range of style proves the tuning's versatility and wealth of potential. In all the pieces, though, there is a pleasure taken in tiny intervals of 25 to 50 cents - as voice-leading, as melody, as complexly buzzing sonority. And so the style, in every case, can be described as hyperchromatic.
Let me put it more simply: I'm trying to make microtonality attractive and seductive, not scary as it is to most people and in most microtonal music. A lot of people, mostly composers, want to hear the most weird-ass and transgressive s**t I can throw at them, and I try to gratify that in some movements. But more, I want to suggest (and prove) that we can keep conventional tonality and augment it with higher-overtone relationships. The simpler the context, the clearer microtonality's potential becomes. This is my strategy for bringing microtonality into the mainstream, where I am convinced it will eventually end up. The goal here is no less than to reinvent tonality.
(From www.kylegann.com/Hyperchromat...)