"Just intonation," as the name suggests is an expression of the simplest possible harmonies using exact, harmonically accurate sine tones. The A440 tone sounds at the beginning of the piece and persists at the same level and position throughout. Seven sequences of tone additions occur. In sequence one, the A440 tone is joined by a tone three octaves below, with additional higher octaves joining in each bar, up to the third octave above the initial tone. These are then pared back again until the 440 tone is heard on its own once more. In the next sequence the same octave tones are present but they are joined simultaneously by perfect fifths above the tonic. These are at exact X1.5 frequency multiples in contrast to the situation if played on an equal tempered instrument. In the third sequence the original octaves are joined by major thirds, being at exact X1.25 frequency multiples. These contrast even more starkly with equal tempered sounds, where the third is significantly different in frequency. In the fourth sequence both the fifths and thirds join the original octaves. The middle of the fourth sequence is the exact centre of the piece.
To emphasise the 2:3:5 frequency relationship of the tone sequences, the basic A440 tone is imaged directly centre forwards in the soundstage and is stationary. The A440 related octave notes rotate around the stage twice in the bar, the X3 related fifths rotate three times in the bar and the X5 related thirds rotate at 5 times in the bar. This rotation direction is anticlockwise in the first half, but the direction of rotation changes at the exact centre of the piece. The second half of the fourth sequence and the fifth, six and seventh sequences are exact mirror images of the sequences in the first half. In this way both the rotation and tones form a mirrored second half, as if a time mirror was positioned at the halfway point. Precise looping of the piece is possible as it both begins and ends at the upward zero crossing point of the A440 tone in a sample accurate way. All tones are phased locked, so not only is the harmonic relationship unusually accurate but the resultant sound appears more as a single organ note or chord than many indivdual tones.
Coherent tones were generated with four instances of Helios sampler and surround panning was achieved using B-format VST plugins in Cubase with pan automation.
Just Intonation is one of the pieces on my CD-R Colossus which is available in the USA from
or directly from myself at this address: http://homepage.ntlworld.com/henry01/ambitunes/ambitunes_records.htm