• Friday June 16 | 9:00 pm11:00 pm

    Chris Brown: Six Primes


About Chris Brown

CHRIS BROWN, composer, pianist, and electronic musician, makes music with

self-designed sonic systems that include acoustic and electroacoustic instruments,

interactive software, computer networks, microtonal tunings, and improvisation. His

compositions are designs for performances in which people bring to life the musical

structures embedded in scores, instruments, and machines.


He is a member since 1986 of the pioneering computer network music band The Hub.

Throughout his career he has composed solos for acoustic instruments with interactive

electronics, and for computer alone, using software he writes for his compositions and

improvisations. Since 2005 he has written music in just intonation, often integrating

rhythmic structures that parallel the proportions used in their tunings. His performance of

one of these works, Six Primes (2014), for piano in 13-limit just intonation, was released

in 2016 on New World Records.


Recordings of his music are available on New World, Tzadik, Pogus, Intakt, Rastascan,

Ecstatic Peace, Red Toucan, Leo, and Artifact Recordings. He has also performed and

recorded music by Henry Cowell, Luc Ferrari, José Maceda, John Zorn, David

Rosenboom, Larry Ochs, Glenn Spearman, and Wadada Leo Smith; as an improvisor he

has performed and recorded with Pauline Oliveros, Fred Frith, the Rova Saxophone

Quartet, William Winant, and Frank Gratkowski, among many others. He teaches at the

Center for Contemporary Music (CCM) at Mills College in Oakland, California.


About Six Primes

Six Primes is a suite for solo piano composed using the six prime numbers 2, 3, 5, 7, 11,

and 13 to govern both its tuning and temporal structure, including harmony, rhythmic

subdivisions, and form. The piano is retuned in a just intonation in which the 12 notes are

tuned to one ratio with the highest prime factor of 2, three ratios with highest prime of 3,

and two ratios each with highest primes of 5, 7, 11 and 13. This creates a great diversity

of interval relationships: whereas 12-tone equal temperament has just twelve distinct

intervals, this tuning has 75. Just intonation schemes often do not employ prime number

ratios that exceed 7, since ratios using 11 and 13 are quite remote to learn to hear and

tune. Similarly, most rhythmic relationships in common use are subdivisions of 2 and 3,

less often 5 and 7. As each higher prime is added to the vocabulary, new musical

experiences obtain. This harmony-rhythm composing method was pioneered in the early

music of Henry Cowell and was played by a few adventurous performers and by his

Rhythmicon machine.


To explore the complexities of 75 intervals, each of six pieces in the suite use just four

prime ratios at a time, defining their own harmonic-rhythmic modes, and each section

within each piece explores a particular subset of it. The length of each section is also

proportional to the sum of these numbers. The purpose is to be able to listen to and play

all of the possible relationships within each piece, each for more or less an equal amount

of time; and within the entire set of six pieces to explore all 75 ratios equally and

thoroughly, regardless of their simplicity (consonance) or complexity (dissonance), and

avoiding progressive schemes of leading from one of those qualities to another. The

materials of the music speak for themselves with their own expressive qualities, whether

or not the mathematics defining them are recognized.