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from Artifact web pages put up by Tim Perkis, Artificial Horizon cd art 1003 1989 downloaded may 14 1995 1575w

ARTIFICIAL HORIZON

ART 1003: Music for New Software Instruments

by JOHN BISCHOFF and TIM PERKIS

"For us, composing a piece of music is building a new instrument, an instrument whose behavior makes up the performance. We act at once as performer, composer and instrument builder, in some ways working more like sculptors than traditional musicians. "

Tracks:

* TOUCH TYPING Perkis * NEXT TONE, PLEASE Bischoff * ENGAGEMENT Perkis * DOVETAIL Bischoff/Perkis * ARTIFICIAL HORIZON Bischoff * CLICKS Perkis * CLAVITRON 6000 Perkis * AUDIO WAVE Bischoff * HAPPY TRAILS Bischoff/Perkis

"The body characterizes everything it touches. What it makes it traces over with the marks of its pulses and breathings, its excitements, hesitations, flaws, and mistakes.... To those of us who love and honor the life of the body in this world, these marks are precious things, necessities of life." --Wendell Berry

But what is the "body" of the computer? The computer is a clock of extreme regularity, which measures out time in millionths of a second with unvarying precision. It performs as instructed precisely the same every time. Its "pulses and breathings" take place on the scale of nanoseconds, and its predictability appeals to those composers who crave precision, repeatability, control.

We're not those composers. There is another feature of the computer that attracts us: its ability to build systems of interaction with complex dynamics, systems only partially predictable, which can develop a unique"body" of their own. These woolly computer instruments can also be designed to respond to players' actions in new ways, creating a music which contains the trace of human gesture, in addition to having a degree of autonomy. In fact, for us, the distinction between composing a new piece of music and building a new instrument is not clear-cut: composing a piece of music for us IS building a new instrument, an instrument whose behavior makes up the performance. We act at once as performer, composer and instrument builder, in some ways working more like sculptors than traditional musicians. And in each case, the focus is on creating a system as open and alive as possible, bearing the precious marks of an individual character.

NOTES FOR TRACKS:

TOUCH TYPING

Composer: Tim Perkis Performer: Tim Perkis Duration: 5'52" Recording: Mills College Concert Hall on 4/14/89

This piece grew out of attempts to build a work based on the behavior of genes in biological systems. I've used a simplified model of sex and mutation: A string of bits defining a sound event (a "gene") is randomly mutated--one bit, selected at random, is flipped--or the entire gene is cut in half and mixed with another one. These actions are all done under the control of keys on the computer keyboard, which either play events ("express" the gene), cause a mutation to happen, or cause an event to be"bred" with another. This set of controls defines an instrument, which I freely play in the performance: I fill the role of natural selection, by choosing to keep some sounds and discard others.

NEXT TONE, PLEASE

Composer: John Bischoff Performer: John Bischoff Duration: 6'46" Recording: Mills College Concert Hall on 4/14/89

The program for NEXT TONE calculates and plays a series of variations on 3 harmonic phrases. As each phrase appears, a performer may select embellishments or changes in articulation of the phrase. All embellishments and articulations occur at whole number subdivisions of chord durations. Chord durations, in turn, are based on simple subdivisions of the phrase length (3, 4, 5, 6), with the addition or subtraction of small offsets in the upper parts. The chords are tuned in 31 tone equal temperament. The resulting harmonic fabric unfolds with just a touch of forward momentum. Broad harmonic changes occur through shifting patterns of intermediate changes. This elaboration of the moment of change tends to diffuse the location of a musical present and induces a kind of global experience of time.

ENGAGEMENT

Composer: Tim Perkis Performer: Tim Perkis Duration: 6'15" Recording: Mills College Concert Hall on 4/14/89

The system creating this piece is set up as a world of thirty simple repetitive players or agents, each with its own little job to do. For example one might have the task of increasing the loudness of the next note played in one of the eight voices. Similar agents would decrease loudness, change pitch (in 31 tone equal temperament), or actually cause a note to sound. Each agent waits a certain amount of time and then does its job again, repeatedly. But all of these agents also have powerful side effects: each time one "goes off" it not only does its own special task, it also slightly changes the rate at which all the others repeat. The resulting system of inter-action is much too complex to understand. As a performer I have controls which allow me to make very general changes in the statistical distribution of these rate changing influences, responding to the surprises the piece deals me.

DOVETAIL

Composers: John Bischoff and Tim Perkis Performers: John Bischoff and Tim Perkis Duration: 6'09" Recording: Mills College Concert Hall on 4/14/89

This piece embodies some of the basic concepts involved in our work with The Hub, a microcomputer network band (The Hub CD is also available on the Artifact label). In many of the works of the Hub, individual composer/performers bring self-sufficient algorithmic computer music pieces, and a new group piece is created by combining these pieces. The modifications each composer makes to make his piece responsive to the others, and the negotiations this requires actually form a large part of the musical life of the group music. In Dovetail, we try to create a space for our two separate processes to speak and respond to each other.

ARTIFICIAL HORIZON

Composer: John Bischoff Performer: John Bischoff Duration: 8'57" Recorded: Mills College Concert Hall on 4/14/89

This is a live mix tape piece that was composed for a dance by Evangel King called CROSSES AND VEILS. It uses two main sound sources: the sound of a steel foundry I recorded in Oakland, California and just-tuned harmonies produced on digital oscillators. The locus of the piece moves from the foundry sound to the just-tuned chords; sections within that motion are formed by radical shifts in mixing and filtering of the materials. The two sound sources represent the "crosses" and the "veils" in the title of the dance, while my title refers to an imaginary horizon line that I envisioned as a setting upon which the motions of the dance could be traced.

CLICKS

Composer: Tim Perkis Performer: Tim Perkis Duration: 4'04"

I like to think of this piece as unlike any other; it in fact is not a sound recording at all. Most pieces on this disc are recordings of live musical performances. But this piece is just a pattern of digital information, generated by a special purpose signal processing computer I built, transferred to digital tape and then to CD, without ever being a sound until it gets to your speakers. I hope it reveals the immediacy of the physical situation: you have a piece of electrical equipment which is flicking around a cardboard cone. The speaker is making the sound, and I suggest you listen to the speaker, rather than listening "into" it for the spatial illusion all sound recordings create.

AUDIO WAVE

Composer: John Bischoff Performer: John Bischoff Duration: 10'35" Recording: Philip Perkins' Studio on 10/12/89

Two idiosyncratic 8-bit waveform generators of my own software design make their sonic motions as a solo performer steers them around by activating keys on their respective keypad controllers. The keys trigger functions such as: hold a sound, change tempo, change pitch range, repeat last three events, etc. The program for this piece was built in 6502 machine code on a KIM-1 microcomputer. Unforeseen sonic features that arose during the development of the program were often incorporated into the music. A guiding notion in the creation of the piece was the idea that the mechanism of the computer could be embraced in the same way that acoustic musicians embrace the mechanical nature of their instruments. In this case, the software and hardware are the "mechanism" that is reflected in detail in the sound.

HAPPY TRAILS

Composers: John Bischoff and Tim Perkis Performers: John Bischoff and Tim Perkis Duration: 6'23" Recording: Philip Perkins' Studio on 10/12/89

As in Dovetail and the Hub pieces, this number was an attempt to create the sense of a space of sound events which hear each other and move and act freely in response to each other. The sound events or atoms in this piece are different than in any of the other pieces. Some of them are musical phrases written by Bischoff; others are "exclamations", sounds created by Perkis playing his Mouse Guitar instrument. The musical phrases here are cut loose from their usual use: they don't serve to mark a place in a progressing musical form, but rather serve as signs of responses in an open musical environment.

A R T 1 0 0 3 (c) 1989 TIM PERKIS & JOHN BISCHOFF (BMI). All rights reserved. ARTIFACT RECORDINGS, 1374 Francisco Street Berkeley, CA 94702 U.S.A.

Recording Engineer: Philip Perkins Special thanks to: Chris Brown, Philip Perkins, Ross Gualco, Jim Callahan, and the Piedmont Piano Co. Design: Michael Sumner


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