Heptadecatonic Drops

for MIDI Instruments in 17-tone equal temperament (1989/90)

Heptadecatonic Drops is the first of several pieces in 17-tone equal temperament (17TET). Prior to the composition, I spent approximately two years exploring musical tunings from the following points of view: 1. equidistance, 2. high stability, and 3. intelligibility of the harmonic-melodic processes. I finally selected the 17-tone tuning which is marked by a closed circle of 17 almost just fifths. Upon completion of my score, I realized the computer version (using MIDI) in the following way:
To avoid the manual entry of approximately 80,000 characters I elaborated a number of algorithms that would allow me to recompose the score automatically. Afterwards I edited the data files manually.

Formally, the three movements Prolog, Etude, Epilog – although derived from the same musical material – are arranged in a thesis-antithesis-synthesis manner.


Creation/revision date: 1989/90

Duration: 8′

Premiere: Berkeley, February 2, 1992

Publisher: Thürmchen Verlag



(Kölner Stadtanzeiger, May 12, 1989)Hajdu’s studies to “Double Concerto” [original name for “Heptadecatonic Drops”] for two pianos –clearly structured, with rhythmically and motivically pronounced frame movements–were also convincing. The composer contrasted it with a computer-controlled version for synthesizer, in which the octave is subdivided into 17 steps. A musical plead that different tunings can indeed coexist.