Imaginary Harmony takes as its raw material a 25-note-per-octave "scale" built by octave-reducing the set of harmonics used by La Monte Young in his 1990 sine wave installation "The Prime Time Twins in The Ranges 576 to 448; 288 to 224; 144 to 112; 72 to 56; 36 to 28; with The Range Limits 576, 448, 288, 224, 144, 56 and 28".
The scale is divided into three segments. Each segment is expressed by a sine-wave that plays a randomly-selected sequence from its segment; each voice proceeds at its own independent pace. Simultaneously with each voice we hear a chord that is mathematically derived from the relationship between the sounding pitch and the scale base frequency of 240 Hz. Underlying all of this is a slowly-pulsing, nearly subliminal 60 Hz binaural pedal tone, where each of three binaural pairs is based on the ratio between a set of high-numbered twin primes.
Part 1 uses harmonies based on multiplication, division, and the Pythagorean means (arithmetic, geometric, and harmonic). Part 2 uses harmonies based on difference and summation tones.
The piece is generative; that is, the specific tone choices from which the chords are generated are selected by a randomized process such that every real-time performance of the piece is unique. Each track is a different rendering and thus they have different tone sequences.
Sine waves are the only sound source. The original sound files were generated by Csound. They were then post-processed (also by Csound) for convolution reverb using an impulse response made at Hamilton Mausoleum in Hamilton, Scotland. Finally, the tracks were normalized in Audacity.