Sensor-embedded data glove for the viola

Part of a dissertation project | Brown University

The goal of this project was to design a transparent but robust controller for string instrument players. Gloves and other devices (bow-mounted hardware, etc.) built for this purpose have traditionally focused on categorizing canonical gestures as a priori objects, e.g., the recognition of martelé, spiccato, or detaché strokes. By contrast, the alto.glove traces the movements of the bow as continuous parameters. This is a performer-centric approach in that the performer is not encouraged to actualize particular strokes for discrete recognition. To the extent that the system rejects such codifications, it favors continuous substrate over articulation, play over telos, and thus—in the most emphatic sense—music over language, Dionysus over Apollo.

Favoring play over telos can be formalized in this question: how does one make a glove that is, in this case, viola-specific while affording uses beyond its intended purpose? In other words, how do you make a glove that survives itself and survives in spite of itself, which is to say, in spite of each of its determinate qualities, to the exclusion of others? Expressed as an imperative, the question suggests: add extra buttons and sensors that at present have no ostensible purpose.

Aside from technical concerns like weight and transparency for the string player, the choice between designing a sensor system that directly reads certain parameters of stringed instrument playing — for instance, the distance of the frog of the bow from the contact point with the strings, whether one is making an up or down bow, the type of stroke, etc. — and one that indirectly reads these parameters via the hand as a “proxy” for the real thing (the angle of the wrist as a rough indicator of the bow’s contact point with the strings) is a kind of philosophical decision. What I mean by “philosophical” here is that this initial orientation produces a system that has something unique to say about the nature of musical gesture. The system that treats certain contortions or motions of the right hand as a representation of something “objective” will probably be frustrated by how volatile that relationship really is. A rough correlation would have to be acceptable, and discrete categories (we’re at the frog, middle, or tip of the bow) rather than continuous and more “precise” measures settled for.

One might soon realize that this lack of precision is not a privation; instead, rather than thinking of the hand as a proxy for something else, the dance of the hand, the vicissitudes of its relationship to the so-called objective parameters, is understood to be meaningful in itself, perhaps the more essential musical gesture, the faltering correlation a symbol of something more expressive, evolving in time through tension and relaxation. The evolution of this system may produce the image of an instrumentalist without an instrument, an air-violist — what would be more entertaining than that? On the other hand, if the proxy idea is pursued, or if more direct measures of the instrument tool are employed, the system that evolves from this may provide the instrumentalist with greater conscious control of certain aspects of the system, owing to the fact that the position of the bow tends to reside closer to conceptual consciousness, to be present-at-hand, to use the Heideggerian locution, than the position of wrist, which is so intuitive and familiar that it recedes much further into the background of experience. The facet of conscious control, of making certain parameters of playing available as genuinely “augmented” gestures that exceed traditional technique — but, and this is crucial, without undermining it — this is still another place where that initial orientation of direct or indirect measure will set things in a particular direction.


The alto.pedal extends the functionality of the alto.glove by taking over macro-scale, structural functions. The pedal is powered by a rechargeable lithium battery, communicates with the computer via wifi, and is outfitted with a bright LED display panel that can be programmed to show "scene" or other information for a particular piece. Two 1/4 inch inputs allow additional pedals to be connected to add even more functionality, such as looping or sustain features.

Alto.glove v2

Alto.glove has gone through several revisions. These were the tasks in the latest version:

  • Embed the 9DF chip into the main PCB, since I suspect this location will provide better bowing data, while also making the glove more reliable by keeping all serial connection internal. This required removing the haptic motor controller breakout board, which I replaced with a 2n2222 transistor and 4001 diode.
  • Flip the PCB orientation so the wires come out of the rear, towards the elbow. The reason for this is that the wires tend to bend quite a bit when the wrist is raised, causing stress and reducing their integrity over time.
  • Individual ground connection for each of the flex sensors, which makes construction of the glove much easier. (The two FSRs, however, share a common ground.)
  • Remove the flex sensor from the first joint of the 5th finger, add a flex sensor to the first joint of the index fingerAfter working with the first version, I discovered that the second joint of the 5th finger provides the most relevant information about bow grip. While the index finger does not provide much useful information about bowing, this placement gives the system a broader representation of the hand's position.



Circuit-bent / Home-brewed instruments 

Instrument building as egalitarian praxis.

Turn on the radio and tune it to a “dead spot” between stations or at the end of the dial. Lick your fingertips, like a safecracker in a film noir. Touch the circuit board lightly in different places with your fingers until you find a location that affects the radio’s sound.
— Nicholas Collins

I encourage thinking of music as gestural activity. The boon of this frame is that it affirms the latent haptic, auditory, and visual expertise of individuals regardless of their individual training, a perspective which opens the door to valuable exchanges among both beginning and advanced students. The ethos of circuit bending and hardware hacking suspends notions of propriety: questions regarding purpose and expertise are recast as questions about the sonic potentials of (ostensibly) non-musical objects. Every individual becomes capable of making unique and valuable contributions to the work, regardless of academic specialty or focus. In an atelier setting, communication among students becomes egalitarian, open, fecund, and avoids the trap of codifying traditional parameters of musical expertise. Furthermore, this context allows light to be shed on the meaning(s) of other musical practices.

Anything that dies has had some kind of aim in life, some kind of activity, which has worn out; but that does not apply to Odradek.
— Franz Kafka, "Cares of a Family Man"

With regard to an instrument's "survival," I want to emphasize that this potential does not point to the “future” but to the ever-present, virtual determinations of the instrument—determinations that have nothing do with a tripartite temporal schema in which the present may be outlived and a future arrived at that no longer knows what an instrument “is,” or, what amounts to the same thing, is “for.” The loss of faith in teleology goes back to Kant's Critique of Pure Reason, where physico-theology fails because, as Kant says, “the step to absolute totality is utterly impossible on the empirical path.” In Nietzsche, genealogy takes its place. The possibility that a text may outlive itself contradicts the pretense of classical hermeneutics, namely that a text has a meaning that can eventually be arrived at via astute philological probity. The meaning of a text is not the intention of its author and can never be, because the polysemy of linguistic signifier resists being tied down to determinate significations or static contexts. Modern design practices take, or should take, their cue from this law, most emphatically in the hubbub of urban planning, where living and working spaces have to be made in such a way that they anticipate per impossible radical changes in local surroundings and social structures. That task fails more often than it succeeds. But the genealogical principle also implies that failures may actually be vital successes.

The same principle ought to inform the design of musical instruments, though the strategy is complicated by the fact that, in the realm of computer-mediated music, the technological substrate of the instrument ages rapidly. This is a tendency of the digital instrument. Of course, the “survival” of the instrument does not so much concern the “actual” amount of time the instrument is around, but is, rather, the signature of its potential.

Adorno advocated working with the obsolete: it is his prescription for unlocking what is or can be “new” in music. He writes of Mahler, “because his material was obsolete, the new not yet set free, in Mahler the antiquated, what had fallen by the wayside, has become a cryptogram of the sounds as yet unheard that follow it. In the negativity of his music [is]…the trace of past suffering.”⁠ What is distinctive about Mahler’s music is the “colliding and mingling” of disparate, anachronistic materials. In the endogenous decay, in the internal calamity of this forced and fracturing synthesis is the cryptogram of truth. Truth, for Adorno, is among other things what the present—always already a tyrannical situation—excludes, namely the image of the other or the “non-identical,” as he calls it. In this context, truth is the “as yet unheard.” Truth is the truth of the “new” that is not conjured out of thin air but rather is discovered as a latent possibility in the discarded. There is more life in the dying than in life “itself.”

Take this principle and apply it to the situation of musical instrument building; now it no longer appears that the outdated tools and sundry materials in use are cause for concern when it comes to the survival of instruments. For Adorno’s principle can also be understood as a commentary on thinking and making in terms of affordances: we encounter an expired object, but in tinkering with it and (mis)using it discover in it more life than anything living, that is to say, more life than anything sanctioned by the normative present, viz. the status quo of culture and its industry. The object outlives itself, and the new comes to fruition via the obsolete. Moreover, the outliving gives way to the truth of non-identity. In the Heideggerian terminology, it is truth in the manner of disclosure or aletheia.

It is not incidental that, when applying this principle to the ethos of circuit bending, Nicholas Collins directs the nascent circuit bender to begin her exploration at the exact point where the radio is allegedly at its most ineffectual and useless, its “dead spot...

4 x 4 Matrix Mixer

Sequencer with resistive touch pads

Toxic Ocean: a quartet of homemade instruments

with Jason Rabie, José Fernández Liermann, Dan Putnam | Brown University | October 2014