Aleatrons are circuit-bent keyboard instruments. Their behavior is often erratic and unpredictable. They crash. But they are also capable of exquisite aleatoric, or chance, musical forays. The original instrument, a Casio mini-keyboard sounding about as good as these small keyboards get, sounds quite beyond its class with the new line output feeding an EQ, reverb and a hi-fi amp or recording system. In addition, while it would be difficult to make the SA-2 sound like a full-blown professional synthesizer, the circuit-bending process does widen the frequency response and some very powerful voices do result.

The Eyed SA2 Aleatron is a mid-version SA2 Aleatron.

The Eyed SA-2 Aleatron's two chance triggers, each a special push-button switch coupled with a threshold dial, are used to throw the instrument's digital logic systems off track. This results in either odd tonal production or chance musical composition, or both. These aleatoric passages may be short or long in length, again decided by chance. The effect is often that of a small, live improv group... piano and drums, perhaps bass, with an odd accompaniment instrument appearing here and there. Alien forms of jazz emerge, abstract tone clusters rise and fall... a valid music mind, though insane, is released.

As is often the case with aleatrons, the behavior of the musical keyboard is unpredictable. Often there is no response from the keyboard at all. At other times pressing the keys will alter the music/tones in progress in various ways. Tones may be pulsed, the key of the music in play might be shifted, aleatoric production might be modified in numerous unforeseen ways.

Two body-contacts are wired to the Eyed SA-2 circuit. These connect the player electronically to the instrument. Electricity is then conducted through the player's body just as it is through any other component on the circuit board. Touching these small brass balls advances the aleatoric patterns in progress. This is a nice way to increment the aleatoric passages in small and delicate steps.

Other of the new additions include a reset switch, a speaker switch, a gold-plated RCA line output, and a red LED flashing inside a glass animal eye bulging from the distorted case and serving as a peak indicator.

The instrument is finished with a multi-coat process involving fluorescent pigments in combination with gold veining, laser-etched prismatic dust and final gloss. New controls designations are hand-inked.

More from Reed's EMI article on the SA2 Aleatron:

"All fields have their hallmarks. My experience with circuit-bending has, over a period of thirty years, resulted in the development of several distinct technical categories born of the process, each best represented by a specific instrument or two. These main categories would include body-contact control, human voice synthesis, digital samples, the equal-tempered scale and, lastly, aleatoric instruments. That is, chance composition devices. I've come to call instruments that produce aleatoric music through the electronic process of circuit-bending aleatronic instruments, or the result of aleatronics.

"But how about an instrument that stretched beyond single category and represented the entire scope of circuit-bending's possibilities? An instrument that involves body-contacts, human voice synthesis, digital sampling, the equal-tempered scale and automatic chance composition. All present and in fine example. That would be a true hallmark instrument.

"Such an instrument exists. This instrument is the Casio SA-2, a small 32-note keyboard with a large set of built-in sounds to work with. There are thirty-two accompaniment patterns for circuit-bending to reshape. These include seemingly sampled percussion instruments whose high-quality recording really shines through, adding a sparkle of live performance to the countless (re)arrangements now obtainable. A bank of sixteen instrument voices is also provided. These may or may not be sampled. They are, however, high-quality voices, most with rich overtones. While the keyboard is described as only 2-note polyphonic, circuit-bending seems to change all this. In fact, very complex pitch clusters and orchestrations result from the new anti-theory electronics.

"A single push-button trigger switch and body-contact are sufficient to nudge the SA-2's programs into wondrous disarray, resulting in original composition sequences looking to the five categories above...

"Here the body-contact, rather than implementing pitch-bend or other frequency shaping as is its function in many other circuit-bent instruments, is used to advance the aleatoric musical structures. A delicate touch upon the brass contact increments the rhythmic and tonal frameworks at the heart of the chance compositions, continually pushing them forward into new combinations of indeterminate events.

"In the realm of human voice synthesis ... no, the SA-2 does not come supplied with such capabilities. Still, on a number of occasions, startling human-like vocalizations arise. Murmurs, chants, shouts and odd singing might materialize and disappear as the music evolves. The emotive effect of these shadowy utterances can be powerful and revealing ... a Rorschach image in sound.

"Digital samples are fascinating to dissect under the diffracted light of circuit-bending. As mentioned before, the SA-2's percussion sounds seem sampled, and all voices involve a digital capture scheme that has them nicely rendered in accessible sound files (probably Pulse Code Modulation).

"Whereas analog signals tend to deteriorate into static-like decay when exposed to certain circuit-bending applications, digital signals break-down into distorted routines rather than distorted tones. The tones can therefore remain sharp while their harmonic content, envelope and assembly behavior is altered. Likewise, just as it is with the musical notes, digital percussion sequences are similarly transformed. Cymbals become backward gongs, kick-drums blend into bass lines, snare drum decays are frozen into crystalline seas of sizzling metallic hiss.

"Generally, keyboard instrument = equal tempered scale. The very nature of circuit-bending places it in the opposite corner of this scheme of order, from conceptual foundation to vocalizations. Perhaps this is why the combination of the two conflicting sensibilities can be so catalytic. Here, within the circuit-bent SA-2, there is created a riveting interface between these two disparate worlds, elements of the familiar bound together by an invasive disorienting matrix.

"As mentioned, central to prompting the SA-2's electronics into unique tonal synthesis and aleatoric music production is a push-button triggering switch, the most important circuit-bending addition. This switch disrupts the instrument's program routines. Several choices exist as to where to connect the switch to the circuit. Any of these will initiate aleatoric composition. In use, with or without keyboard keys being held down, and with or without a rhythmic accompaniment playing, the musician quickly and lightly taps this push-button switch while listening to the results.

"Any number of things may happen. The entire circuit may crash. Silence. No response anywhere until the main power switch is turned off and back on. More than likely, the keyboard will become inoperative while the sound circuit, cautious of the strange knock, decides whether or not to answer the door. Many knocks might go unanswered. But when this obscure door does open to the world of anti-theory electronics, I've learned that anything might appear.

"It could be a haunting voice, a single note of beguiling texture perfect for capturing as a sample and flying into a full polyphonic keyboard system. Abstract sounds might come forth ... tangles of sustained noise and pitch with evolving tonal clusters buried within.

"Pushing the switch might cause a loop to begin. This loop could be percussion instruments revolving in odd rhythm, abstract sound cycles, musical notes repeating a melody, or combinations from dense to sparse of all elements working together. These repeating sound-forms may slowly fade away, hold steady or accelerate to crescendo.

"Pushing this digital trip-wire will also, every so often, launch an aleatoric episode such as those described before. This chance composition, like certain loops, may also slowly accelerate to crescendo ending in any number of resolutions including tone clusters, silence, loops, pre-programmed rhythms or, occasionally, a new aleatoric sequence possibly again increasing in tempo through another complete cycle. The keyboard may or may not be active during loops and aleatoric passages. If so, it may or may not behave as usual, sometimes pulsing disassociated notes, producing sound effects or even modifying accompaniments in progress.

"Pushing the same triggering switch during aleatoric progressions can shift elements within the music, altering perhaps the percussion pattern, the choice of lead instrument, the accompaniment scheme or a number of other sonic aspects effecting the flow of indeterminate composition. Again, pushing the button represents a certain degree of risk, not at all unfamiliar to circuit-bending, that could result in program crash. While it's true that the lost sound-form is probably gone forever, impossible to achieve in exactly the same way again, the bending process balances this out here and in many other instruments by providing a bottomless well of possibility for yet unheard musics, a chance to give life to new and unique sonic creations every time the circuit is turned on."



Price for the Eyed SA2 Aleatron is $1,200 plus shipping.
This instrument is also available as a Bare Bends model. See the Bare Bends Gallery.


POB 20181
Cincinnati, OH 45220