Music by Dave Seidel
Palimpsest
Posted 13 May 2007, 10:58
Description
A meditation on remembrance, breath, stasis and change.
Duration: 10:58
Background & Technical Details
Palimpsest is the second in a series of works that began with Owllight (although it remains to be seen whether or not the series will continue). While the pieces have very different moods, they both employ cellular automata as a kind of structural template, and both are built from very simple materials: sine waves, some reverb, and very few notes.
As in Owllight, the harmonic spectrum of every note is determined by the successive states of a simple one-dimensional cellular automaton (in this case, Rule 57) as shown on the right. The states start at the top of the image, with one state per row. A row consists of a series of “cells”, each of which is either “alive” (black) or “dead” (white). I treat each cell as a harmonic (i.e., an integral multiple of the base tone), so the more cells that are “alive”, the richer the sound. Each harmonic is made by an individual sine wave tone.
Palimpsest consists entirely of two two-note chords: 60Hz + 90hz (3/2, a just perfect fifth) and 67.5Hz + 90Hz (4/3, a just perfect fourth). Each chord proceeds through the series of spectral transformations represented by the diagram, but the chords are offset by the exact duration of a single state (the perfect fifth starts, and the perfect fourth follows), so that the chords alternate throughout the piece. In addition to the spectral changes, change occurs at two other levels. The length of the state (the “beat” of the piece) continually decreases at a slow rate, which provides an almost imperceptible sense of acceleration. Also, with every successive “beat”, the individual tones that make the harmonics are arpeggiated at a slightly greater rate, so that the chords get progressively more “smeared” over time; you can hear this most clearly on the very last chord in the piece.
This piece is dedicated to Carter Scholz, whose album Eight Pieces continues to inspire me. (Scholz co-wrote a very interesting sci-fi novel called Palimpsests that was published in 1984, but I had already named the piece before I remembered the book.)
Copyright & Licensing
Copyright © 2007, Dave Seidel. Some rights reserved. This work is licensed under a Creative Commons Attribution License.
Files/Downloads
MP3 (25MB, 48K/16-bit, 320kpbs)
OGG (20MB, 44.1K/16-bit, 221kbps)
blue & Csound project files (102KB)
Tags
cellular automata, just intonation
hi dave,
your sounds are attending me for a while now…
nice to come back and listen again
— daniel lercher 10 February 2008, 09:01 #