received from m. trayle on july 3 1995 copyrighted appeared in Ars Electronica 1994 catalog 2115w

Gates - Seven and Haunted

I haven't put pen to manuscript paper in years. Since the late 1970's I've been using electronic hardware and computer software to fill in the musical details while I've focused my attention on creating larger musical processes and situations. It's not that I'm lazy, it's just that I bought into the Cageian notion of removing ego from the process of creating music a long time ago, and I can't seem to give it up. I also have an affinity for found sound material... for the gritty distortion and electronic artifacts of radio and television broadcasts, the over-amplified flotsam of popular culture.

Fortunate Circumstances

Ever since I graduated from Mills College in 1982, I've made my living programming computers. Thanks to computer industry folk wisdom that musicians make good programmers, and a basic understanding of digital logic design and programming gained as a byproduct of practicing electroacoustic music, I was able to get a "straight job" after leaving Mills.

Since then I've had a succession of such jobs, most of them at least a little interesting in their own right, but not what I'd call musically inspiring. Through a long chain of fortunate circumstances I ended up working at the NASA Ames Research Center in 1987, in one of the first virtual reality labs. I learned enough about VR there to know that a dataglove might make a good performance interface, and that a computer-generated 3D space might be a fertile place to put those Cageian musical processes into action.

Of course at that time VR technology was (and for the most part still is) economically out of my reach. Sometime in the late 1980's Mattel, the American toy company, introduced an inexpensive dataglove for Nintendo video games called the Power Glove. Like the much more expensive datagloves used for "serious" VR research the Power Glove operates within a finite three dimensional field and sends information to a host computer about its location within the field and which of its fingers are bent. The Power Glove also has a set of buttons located on the wrist which send ASCII codes to the host.

The low cost (originally about $80, now about $20 if you can find them) and wide distribution of the Power Glove seemed to suggest that there would soon be one in every home, hooked up to a supercharged entertainment computer of some sort... a player-piano for the 21st century. Sadly, I was wrong, Mattel no longer makes the glove. But that inspired me to write some pieces for the glove that could be played by amateur musicians, with a performance interface simple enough to use that you wouldn't have to study the instrument for years just to play music for your friends after dinner. Virtual chamber music.

I started writing music software for the glove in mid-1990, shortly after seeing a demo at the ACM SIGCHI conference that year, and finding a "gray-market" breakout box that would allow me to interface the glove to my Amiga. The software that I developed (written in Lattice C under AmigaDOS) uses movements of the glove within the field to control the pitch, amplitude, and duration of sampled sounds.

And in keeping with the idea of making an affordable music appliance for the home, I used the Amiga's internal audio system as my sampler. Although it's a low-fidelity 8-bit system its open architecture allowed me to perform tricks with samples, such as changing start and end points in real-time, that you couldn't do with higher-fidelity commercial samplers at that time.


One of the first pieces I wrote for the glove was called Gate. In this piece and the versions of it described below, motion on the horizontal (x) plane is mapped to changes in pitch, along the vertical (y) plane to changes in amplitude, and along the plane perpendicular to both x and y (z), sample length. (It's worth noting here that changes in sample length are generally perceived, in my music anyway, as changes in timbre when the samples are relatively short, about 0.25 seconds or less, and as changes in rhythm when they are longer).

Planes within the field can be defined and made edge-sensitive - passing the glove through one of these imaginary planes will trigger an event or chain of events. I sometimes refer to these planes as trigger planes. The trigger plane defined for Gate runs perpendicular to the z axis at it's midpoint, for the full extents of the x and y axes. This plane is the 'gate'. When the glove moves forward (away from the body) through the plane, the gate 'opens', when the glove moves back towards the body, the gate 'closes'.

Whenever the gate is opened or closed, a sample of a gate or door opening or closing is played. On one side of the trigger plane is a collection of audio samples, I call it 'sample space'. On the other side of the trigger plane is an area where the audio samples from sample space can be played, called play `space'. (see below). The buttons on the glove are used to start, stop or pause the performance, or to load new samples.

Originally intended for performance, Gate was first presented as an installation at Mills College in Oakland, California, as part of the Electronic Music Plus Festival, and subtitled UFOs. Gate (UFOs) was conceived of as an enclosed residential space spanning the fuzzy border between two worlds. A fence was constructed along the trigger plane, enclosing the sample space, with an opening for the gate.

On the sample space side of the fence sat a small table. On the tabletop were about a half-dozen invisible, unidentified household objects, pots, pans, pepper grinders, salt shakers, etc., each represented by an audio sample, each at a fixed location relative to the trigger plane. While the gate was open, an object could be 'picked up' from the table by moving the glove to the object's location and putting the thumb and index finger together. The object was then brought back through the gate into play space, where its sonic properties were explored and manipulated by moving the Power Glove within its 3D field.

Haunted... Real Virtual Estate

In the late 19th and early 20th century magicians and mediums used specially constructed furniture, "seance cabinets", as gateways to the spirit world. With these structures showmen such as the Davenport Brothers or mediums like Mina Stinson Crandon would communicate with the dead. Aided by the high-tech special effects of the day (voice trumpets, pneumatically controlled hands) and a little legerdemain, these "Spiritualists" could create apparitions and manifest spirits. Priests and shamans use special tools and techniques to conjure and then exorcise noisy, rambunctious, spirits from the homes of the living.

Like Gate (UFOs), a seance cabinet or a haunted house, Gate (Haunted) suggests a doorway to another world, a temporary home for telenomadic souls that have gone over to the "other side".

Rather than the table used in UFOs, the samples sit on shelves mounted on a wall. Ropes outline a house and a special room within the house. The back wall of the room is decorated with a relief of shamanic symbols and fetishes and supports two shelves. On these shelves are four ritual objects used for summoning ghosts.

The user enters the house, walking towards the room. She picks up a dataglove from a small table near the door to the room, and puts her right hand in the glove. Reaching through the door to the back wall of the room she hears the door open. She picks up one of the ritual objects with her gloved hand... it makes a sound. She brings the object back through the door into the rest of the house. In this part of the house the sound the object makes changes as she moves the object around. She reaches through the door again to replace the object in its proper place on the shelf, and chooses another object.


I heard a lot of shortwave and amateur radio while I was growing up... my father had been a radio hobbyist since his teenage years and was in the broadcasting business on the Big Island of Hawaii for awhile. The chief engineer who worked at my father's radio station did so as a sideline, spending most of his time working for a defense department contractor. I remember one night he took me with him to a radar test station on the southeastern tip of the island, a remote spot where, local rumor had it, KGB agents came ashore from submarines and blended in with the tourists. The station was full of electronic gear, most of it constantly on and making noise... distant AM radio stations from the mainland, shortwaves, weird military telemetry. Those sounds still resonate for me today.

Seven Gates is an interactive computer music composition, the live performance variant of the Gate series of installations. The performer uses the glove to manipulate invisible "sonic souvenirs", audio samples from the various musical cultures around the Pacific Rim (imagine driving around California with your car radio stuck on "scan" mode).

The piece has seven sections ranging in length from two to five minutes... either a set of "bagatelles" or a sort of "theme and variations" , depending on how rigorously you want to define the latter. As in the Gate series, the stage is divided into two areas: a 'sample space' with invisible 'shelves' and a 'play space'.

Separating the two areas is an invisible 'fence'. This fence runs perpendicular to the z axis at it's midpoint, for the full extents of the x and y axes. The performer, wearing the glove, reaches through a 'gate' in the fence to grab a sample from a shelf, then brings it back through the gate to the play space where its sound can be modulated. The gate is wired for sound, anytime it's opened or closed an audio sample (one of several gates and doors) is played. (Each of the seven sections has a different sample of a gate or door associated with it). While the performer holds the sample (by making a fist) the sample is audible, making the hand flat mutes the sample.

The piece is mostly improvisational, with a few general rules about gestures to use in each section. These rules take the form of seven simple diagrams that define how my gloved hand moves within sample space and play space (see below).

The repertoire of gestures used in the piece is symmetrical: sections one and seven use the same or similar gestures, sections two and six the same, and so on. The central fourth section generally matches the first and seventh... I've been known to deviate from my 'score' during this part. There's a contextual and timbral symmetry at work in Seven Gates as well. The first and seventh sections use samples of Nortena and Pacific Island music, the second and sixth use 18th century European music, the third and fifth use speech sampled from radio and television, and the fourth section is comprised of a combination of the above.

Sometimes people who've seen a performance of Seven Gates ask me if I've been studying Tai Chi or practicing some kind of alternative dance therapy. The answer is a qualified no, although after years of tweaking knobs and moving computer mice it's refreshing to actually perspire during a performance. The relationship between sound and movement is simple and straightforward, and the sound is in charge.

The gestures in the piece are the results of grabbing big chunks of audible cultural references and fluidly shrinking them down to purely electronic timbres... disassembling, reconstructing, and remapping everyday sonic terrain.


Some definitions of the word 'gate' from the American Heritage Dictionary: "Something that gives access","An opening in a wall or fence for entrance or exit", "The structure surrounding such an opening".

Each of the pieces in the Gate series is a detailed exploration of a small set of found sounds. My homebrewed software teamed with the glove gives the performer access to the insides of those sounds, freeze-dried in electronic memory. Instead of immersing the audience member or installation user in an aurally and visually realistic world, I use sampled sounds and a bit of theatrical set design to bring his or her imagination into play.

In the installations UFOs and Haunted representations of fences and walls identify an entrance to this imaginary world. Accepting the invitation to step inside, the user becomes a performer and acts as medium... reanimating sonic apparitions, accessing unheard worlds.