We humans tend to treat our perceptions as holistic—as seeing things as things, instead of as an accumulation of parts, details and features. This is the great abstracting power of the 3-pound neural network in our heads, and is a major differentiating characteristic from other computational paradigms.

The holistic pattern of Deconspectrum is that of the spectrum analyzer, a tool for understanding the components of a sound signal. You’d recognize the spectrum analyzer as the (often colorful) bar graph showing how loud the bass, mids and treble are on a fancy car radio or web MP3 player (which are often just fake animations). These graphical displays are intended to give an insight into the component parts of a signal that complement our own perceptions: we can hear the loudness of the bass or the absence of midrange, but we couldn’t tell you something as specific as how much energy there is at 250hz (at least, not without practice).

Any given sound can be understood as an accumulation of sine waves, a simple oscillation of air. Breaking apart a sound into these components is known as decomposition, and is the basic principal of a mathematical technique called the Fast-Fourier Transform, which gives us access to the raw numbers of a sound, the exact amounts of energy, that the unaided ear can’t provide. The spectrum analyzer supplements our perception by dividing a signal into “bands,” organized by the frequencies of these component parts. Or, at the very least, they give the manufacturers of audio devices something flashy to add to their product.

These tools are always presented as a single whole with a single function, one complete thing that breaks down the features of another perceptually complete thing. Deconspectrum pulls these things apart, eviscerates them, granting their constituents a new autonomy in the form of small luminous cubes that are each tuned to their own frequency band. These bands are mapped to the color of the cube, from yellow to green to blue to red and all the colors in between. They are conceptually identical to the rising and falling columns of the spectrum analyzer, but now spatially distributed and able to be moved and re-ordered—and crucially, still capable of emerging the holistic experience of the sound and its analysis. In other words, Deconspectrum is both the sum and the parts, the spectrum analyzer and its frequency bands, the pattern and the features.

Deconspectrum is best experienced in quiet, when the viewer can whistle, sing or hum distinct tones and see before them their melody reflected in color.

The individual units are completely autonomous, containing their own microphone, processor and color LED, and are also for sale individually as artist editions for $25. As such, they have an additional “standalone” mode that follows the peak frequency of whatever it hears, creating a colorful reflection of a melody, voice or spontaneous noise. They are both 9V battery and wall powerable with any 9 volt+ power supply.

Did you know that the scale of acoustic pitches is logarithmic?  This means that, even though we perceive the scale of notes as increasing or decreasing linearly, the actual frequencies are doubling or halving with each octave.

In my Deconspectrum installation, I’m mapping acoustic frequencies to color.  If I mapped them linearly, the colors would change very rapidly in the low frequencies, and then stop changing as obviously as the pitch gets higher.  This is not the effect you would expect, since you want each pitch to be represented by another color.

The solution is to map frequency to color (hue) logarithmically instead of linearly.  Thankfully, AVR C gives us a handy base-10 log function:

int hueFreq = log10(frequency - FREQ_MIN) * hueScale;

If we graph this, we get:

The ‘y’ scale is hue and the ‘x’ is frequency.  You can see that, with each octave, the change in color progresses more naturally, mimicking our linear perception of pitch.

Here’s the same graph with a logarithmic frequency axis:

The dotted line is the log10 function without the cutoff, so you can see the “simulated” linearity.

Handy, and highly effective!

Vox Mensuræ (The Measured Voice) is a graphical depiction of the quantization of sound, an end result of the process that converts audible waves of air pressure into numbers.  Each row is a single number displayed in binary—filled dots for 1s—with digit significance increasing to the left (just as decimal numbers, like “3,135″, increase in significance from right to left).  The number represented is the volume envelope (the “level”) of the sound coming into the computer’s microphone.

Quantization is not just the foundation of all digital technology, but the core of a fundamental model of the universe: quantum mechanics.  Classical models of reality considered some things to be “continuous” in contrast to “discrete” things; atoms were discrete but ether was continuous, and could therefore be infinitely subdivided.  The central insight in the modern era is that nothing is, in fact, continuous: even the energy levels of an electron land in “steps” and cannot exist in between those steps.

The quantization of sound is also the dividing up of a signal into steps, too small to discern with the naked ear—but when transformed into a string of bits, a stream of suddenly tangible visible information.

Vox Mensuræ is a software application built in OpenFrameworks.  Download it here for OSX.  I’ll try to get the source online so people can build it for other platforms!

PuréeData is a browser-based PureData interface for a remote, central server that allows live, collaborative patching for anyone, anywhere.

Using Pd’s internal messaging system and an accompanying python script, PureéData allows anyone with a browser to modify a public, shared patch running on a server and listen to the results live over an OGG audio stream.

The project is currently in development and is freely available on GitHub.  PureéData is in part adapted from code by Jeraman.

Sketches of possible sculptural forms (these are roughly 8-10″ in height).  The first four are my favorites:

Sound prototyping: A short composition of 4-7 sine wave oscillators harmonizing and disharmonizing:

Two videos of synth design approaches: 8-bit R2R DAC and Schmidt trigger oscillator.

Live @ Monkeytown, May 22, 2009: Continuum.Puncta

In a novel collaboration, artist and composer Ted Hayes combined his languid “function drones” with sonic inventor Steve Litt’s “CrudBox,” a solenoid-driven percussive sequencer, to create a fully analog performance that juxtaposes fields of continuous tones—the continuum—with sequences of percussive beats—the “puncta.”

Ted uses common laboratory equipment—the function generator—with processors from much different contexts, like guitar pedals, as a platform for composing epic, rumbling aural landscapes. Conducted with the aid of artful and detailed graphic scores, he is interested in developing melodies that are just out of reach of ordinary timeframes, resulting in impressions and visions as opposed to discrete themes and leitmotifs.

Meanwhile, Steve Litt punctuated these fields and spaces with the amplified percussion generated by his CrudBox, a handmade hardware sequencer that strikes small samples of varying materials to produce a panoply of alien sounds.

Special guest Adam Harvey showed his interactive KaKoozies: “Combining gesture recognition with beer mugs, KaKoozies is a system for creating kinetic art while drinking beer.”

Thanks to everyone for coming to the show, and special thanks to Lindseytr0n for shooting extra video!

tedbot.com
crudlabs.org
ahprojects.com

Last Tuesday at ISSUE Project Room I performed a new experimental music piece titled “Manifold Voices:”

Thanks so much to my players: Jessie Shaffer, Henry Bigelow, and Matt Boyle.  Read on for lots more information on the piece.

“Manifold Voices” is a musical work for violins and function generators. The function generators—electronic lab equipment for generating simple signals—utilize a graphic score that Matt and I interpreted live.  Here are the first three pages:

The score for the function generators consists of a curve denoting amplitude over time. Pitches are indicated numerically in Hertz, and occasionally arrows indicate glissandi. As you can see, it was continuously revised during rehearsals.  The function generators drove two independent speakers, which were mic’d and run into guitar pedals (an Akai Headrush and a multi-effects bank, respectively), then into Ableton Live on a laptop for delay and reverb, and then into the house mixer.

“Manifold Voices” grew out of two intersecting developments: drone music I had been working on with the function generators (the technological side) and research in musical tuning systems (the theoretical side).  Since the function generators afford the use of specific frequency values, I decided to attempt to write this piece using a Pythagorean tuning system, where the fifth interval is a perfect 3/2 harmonic ratio.  Toward this end I developed a simple PureData patch to automatically generate the frequency values for the diatonic scale.  The violins were tuned down to match note values derived from a fundamental frequency of 250hz.  More details to come…

EggBeater uses the intuitive power of rhythm to let anyone control the playback of music. Shaking this small, wireless device in regular patterns can automatically adjust the tempo and timing of loops. Just start playing the EggBeater just as you would a traditional shaker, and listen as the song slows down as you slow down, or speed up as you do!

EggBeater uses an accelerometer coupled with an XBee radio to send your movements to PureData, where they detect your downbeats and rhythmic tempo. The software can then control playback within PureData or send OSC or MIDI messages to other platforms.

Here’s a short video courtesy of Lee-Sean:

“TwelveStep” is the working title for a wireless dodecahedral step-sequencer and MIDI controller.