Nur (2009, revised 2015), composed and performed using SuperCollider, creates rhythmic structure from acoustical beating patterns using overlapping layers of precisely-tuned tones of long duration. This piece is dedicated to David Borden and Mother Mallard's Portable Masterpiece Company; I was fortunate to hear them perform live (more than once) in their original configuration as Borden, Steve Drews and Linda Fisher, when I was a young teenager living in Ithaca, New York in the early 1970s. Nur (نور) is an Arabic word meaning light.
Nur's layers consist of chords in just intonation; each tone in the chord is generated by ten oscillators in a Risset harmonic arpeggio configuration. One by one, the chords build up and overlap; as each earlier layer dies out, others are added until the end of the sequence is reached. The ratios between the pitches within each chord, and between the Risset arpeggio components within each pitch, are mutually reinforcing and create an interlocking set of contrapuntal beating patterns.
The performer's challenge is to play “in time,” starting each drone layer in sync with the beating pattern established by the very first chord. After the last chord is played, and earlier chords continue to slowly die out, the performer gradually increases the output level to reveal “submerged” beating patterns.
Nur had its premier performance as part of the Unique States concert series at BUOY Gallery in Kittery, Maine, U.S.A., on January 9, 2009.
Hardware: Linux laptop, Scarlett 4i2 audio interface. Software: SuperCollider. Recorded in 48k/24-bit stereo on a Zoom H5 recorder using direct output from the Scarlett 2i4, normalized and exported as a 48k/24-bit FLAC file using Audacity.