Minimalist composer Randy Gibson, curator of the Avant Music Festival, is currently working on a piece for Ekmeles. I’m just starting to explore the sound-world he’s developed, and wanted to share some of the unique aspects of the tuning systems.
Randy is working with what he calls “pillars” of just intonation intervals to build scalar tunings. Just intonation, for the uninitiated, is a tuning system which involves small whole number ratios. These were originally developed by the ancients, and the ratios corresponded to string lengths of simple monochord instruments. Pythagoras is credited with the discovery of these ratio tunings, the simplest of which are derived from the lowest primes. Taking 1 (or 1/1) as the tuning frequency, multiplying by 2 will yield the octave, 3 (expressed as 3/2 to put it within the range of the octave) the pure fifth, 5 (again, 5/4 to drop it into the proper octave) will yield the just major third. You can also think of these intervals as being derived from the overtone series; the 2nd partial is the octave, the third partial the fifth, the fifth partial the major third etc. These perfect intervals were, for various reasons, gradually left behind for tempered tuning systems, which eventually led to the 12-note equal temperament we find on modern keyboard instruments.
The tuning of the piece for Ekmeles focuses on the prime number 7, a ratio favored by Randy’s teacher and mentor, La Monte Young. Most of Young’s seminal work The Well Tuned Piano is in septimal tunings, and the use of 7 is prominent in his work generally. Most simply, the seventh scale degree in this upcoming work will be tuned as 7/4. This is the natural, lowered minor seventh we encounter in natural brass instruments. The majority of the rest of the scale is constructed by building a “pillar” of 7/4 ratios on top of this first 7/4 ratio, yielding, in descending scalar order, 49/32, 343/256, and 2401/2048. Note the powers of seven as numerators (the denominators again function to move these ratios down within the octave range). Much like the simpler ratios noted above, the numerator of the properly reduced fraction also represents the partial to which the note corresponds. This pillar also means that the interval between 7/4 and 2/1, the septimal second, is also repeated between 49/32 and 7/4, 343/256 and 49/32, and 2401/2048 and 343/256. Randy fills out the scale by including several lower primes, 9/8 (a true major second above the tonic) and 3/2 (the perfect fifth, which lies between the 2401/2048 and 343/256 in the scale).
Intervals constructed from lower primes are easier to hear, but Randy’s scale is actually very singable! He’s provided the group with a sine wave drone, which includes most of the pitches from the scale in various registers, so much like Indian classical music, properly tuning these notes is a matter of resonating with the drone. The experience of singing just-tuned music is a physical one, in a way that is difficult to describe. Each interval takes on a unique character borne of its ratio, and the way the waves interfere. The piece is in its earliest stages now, and I look forward to spending the time internalizing this unique tuning system.