Concrete Music (Ethan Bordeaux, Ben Recht, Noah Vawter, Brian Whitman)
Concrete Music, a thirty year “song with life” embedded into a concrete block, was one of a few releases by the forever-nascent DSP Music Syndicate. It won second prize in Vidalife 2003 and was exhibited at ARCO early the next year.
The first twelve minutes of Concrete Music (click the blue arrow to stream, the first 30s are silent)
We investigate the life of a song. As pieces on a CD live the same short existence every time their static bits hit the laser, we would instead like to hear something evolve as we do– making the same decisions and born with the same intuition and biases as the composers who create them. Concrete Music is a living song with a lifespan of 30 years, encased in rough-hewn concrete and entrained to learn from its own decisions while remaining impervious to changes in climate and technology.
To achieve our vision we created a hardware music processor from commodity hardware, a music language robust enough to handle the particular constraints of long-scale time and embedded decisions, a synthesis framework capable of forming timeless textures and then packaged our song permanently in quick-set concrete. We time our song to fall still just as the package’s last drop of water evaporates, causing cracks in the container.
Our song is born with initial conditions, having embedded natural primitives of tone (starting from an A-minor chord), texture (seven sine waves, two triangle waves, two white noise generators, three impulse generators, 2 Karplus-Strong generators), rhythm (sequences of percussive patterns) and critical duration (at year 30 the song stops, not in control of its own longevity.) From these innate parameters the song composes itself by slowly wafting away from its base state. Decisions are encoded as multi-state Markov processes evaluated at both short and long time steps; innateness is embedded as prior probabilities. A small choice early in the song’s life can cause drastic effects later in the dimensions of pitch, rhythm and texture.
As the song learns from its choices, a probabilistic recursive “remixer” samples its own input, analyzes its short-term progress and folds the results back into the stream. The rhythm of the remixer is determined by micro-decisions the song must make every bar combined with larger, song-structure-affecting choices at every few minutes, every hour and every month.
Because of this large scale of compositional drift, it is fundamentally impossible to predict what Concrete Music will grow into as it progresses. We can only listen and wait.
Technical Information
Inside the concrete slab sits hardware powered by an Analog Devices 2187 DSP along with audio codec and flash memory, running on a custom low-power circuit board. On boot the DFS filesystem loads the “Concrete Music” 30 year song program and executes it. The hardware runs at roughly 90 million instructions per second and can store two megabytes worth of program information. It has two outputs and two inputs with expansion for various sensors and controllers. Composers download their pieces to the board using a open-source client application on any computer with a serial port.
The song is written using the “Syndevkit” algorithmic music language developed by Ethan Bordeaux and the DSP Music Syndicate. Instead of coding events at time points we instead code a process that follows a longer clock. Events permute through the song at intervals as fast as 80 times a second simultaneously with intervals as slow as one month and longer. As the song evolves it makes a series of decisions which significantly affect its path later in life. This, combined with the “nature primitives” hardcoded into its flash memory allow the song to live its own life through various Markov processes.
On each boot the song begins anew at 0—to hear the coda one must make sure to leave the Concrete Music piece on and supplied with power for the full 30 years. At the 30th year the song will fall silent.