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Program Note

Pi Day

a computer-generated blues in B-flat

by Reginald Bain

On March 14 (written 3/14 in America) math enthusiasts across the world celebrate Pi Day, a holiday dedicated to the world's most famous mathematical constant. Pi is the ratio of a circle's circumference to its diameter, a constant that appears throughout science and mathematics. Traditionally denoted by the Greek letter π, its decimal expansion begins: 3.14159...

Credit: Wikimedia Commons

My answer to the call for silly salutes to this mysterious number, Pi Day (2009) is a computer-generated blues in B-flat major. The music is algorithmically generated by a computer program (written by the composer using Cycling '74's Max) that maps the digits of pi to pitches in real time. Following a brief introduction, all of the notes are strictly sculpted from the first 512 digits of pi. The digits are artfully mapped to pitches, and other musical parameters, at a constant tempo and pulse in order to create interesting musical lines. The lines are then layered using an additive formal process: first a log drum enters with a steady eighth-note pulse, then a bass line with an idiomatic groove, then woodblocks in canon, then a 12-string guitar takes over, …. Contrastingly, the sampled voice part (spoken by my wife, Erin Keefe Bain) recites the digits at a slower pi-related tempo. The irrational polytempo relation between the foreground music and vocal recitation creates a subliminal rhythmic tension that is not resolved until the voice finally begins its infinity implying fade out.


USC Computer Music Concert
April 1, 2009
University of South Carolina
School of Music, Recital Hall
Columbia, SC

Updated: March 13, 2017