Synapse January/February 1979 magazine article presumably copyrighted 1407w


David Behrman's Microcomputer Workshop by Bob Davis

The most exciting event looming on the horizon of electronic music is the impending shift from analog electronics to digital and digital/analog hybrids. Prominent among those making use of the latest digital technology is David Behrman, co-director of the Center for Contemporary Music at Mills College, member of the Sonic Arts Union, and long associate of the innovative Merce Cunningham Dance Co.

During June 26-29 he presented a workshop in "Homemade Instruments using Microcomputer Technology and Software." culminating in two concerts on June 30 and July 1. This series was part of the artist-in-residence program sponsored by 80 Langton St., a contemporary performing and gallery space south of Market Street in San Francisco.

David Behrman is particularly well suited to introduce artists and musicians to this technology because his background is in music and not engineering. He composes for a musical end product, often intuitively, not for a dry, contrived theory. On the first evening he presented a "program in progress," concerned with mapping the most resonant overtones sung by a live singer.

When the computer is ready to accept sounds from the live mic it signals Behrman's homemade bank of triangle wave oscillators, which emit a gradually rising pitch. The vocalist now sings into the mic and the computer analyses the sound by internally making a type of graph, plotting frequency of the live sound against its amplitude. It records any peaks, i.e. frequencies of the incoming sound which are particularly strong.

When the computer has finished accepting information, the sliding pitch is shut off and the computer then tunes the analog oscillators to play back these overtones. At present these are heard in a strict descending order rather than the order in which they were received. Thus after the initial electronic rise in pitch, with its improvised vocals, there is a shorter fall which highlights frequencies taken from the material just heard. The upwards gliss then begins again as the computer asks for more vocal information.

During part of three other workshop sessions, Behrman arranged for other composers working microcomputers to present their work. Firstly, Paul DeMarinis explained his program for shifting the pitch of an incoming signal in real time without changing its time base. He explained his interest in seeing how far one could push the alteration of speech before the meaning is beyond the listener's comprehension. He found that for this type of pitch shifting, the limits were rather tight, being approximately an octave.

The workshop highlighted the differing approaches of Behrman and DeMarinis. The latter's program is short and could be written on as little as half a page. Behrman in contrast informed us that he was looking over the program for the concerts which he had written over a year ago, and had trouble remembering all the twists and turns as it was over 180 pages long.

"Real Time Computer Network Music" are a trio of microcomputer artists, John Bischoff, Rich Gold, and Jim Horton, who initially developed their programs separately, but later formed an interactive configuration. Data from one microcomputer was fed to the next, and determined part of the sound that the second microcomputer produced or controlled. All three produced a constantly changing exchange that could produce hours of uninterrupted listening, and their piece created a delightful sonic environment to gently move about in, and converse with the musicians about their work.

Bischoff's program was written for an installation at the Works Gallery in San Jose. He was interested in sounds with high noise content of various duration with "relatively long silences in-between" (1/4-1 second). he uses no analog oscillators: the computer produces the saw-tooth and triangle waves; and his program adds "funny sidebands" to the saw-tooth waves to enrich the noise nature of the sounds. The pitch moves in one direction to some varying limit written into the program, then it jumps to the opposite extreme and begins moving in the same direction as before. The length of time of both sound and the silences between is variable, and there are controls available to "Weight the amounts of silence towards one range or another.

The basis for Jim Horton's program is a 29 note scale proposed by the late Max Meyer's theories of melody. In simplified terms, each note that is played limits the possibilities for the next note. Meyer defined a set of rules and Horton's program is written around them, producing very pretty melodic lines reminiscent of Bach, Handel, and occasional hints of The Beatles.

Gold's inspiration for his program was Fictional Culture. About a year ago he began a large piece based upon an imaginary society, and most of the details about these beings and their environment were created and stored on programs. The pitches for the excerpt from this long and involved piece are based on the topology of the imaginary landscape. Thus as an imaginary traveller encounters hills the pitch rises, and then falls for valleys. Each of these trips is in the form of lissajous figures, familiar to those who work with oscilloscopes. Gold commented that it was easy to recognize his program because it could sound like anything.

Phil Harmonic was the final computer artist to present his work. He is interested in microcomputer work which can be used in traditional concert environments as well as "in unusual spaces where such audio-visual presentations are not usually expected." Thus for example, several years ago he presented a piece in a supermarket which greatly amplified the sound of the store for the shoppers. His latest plan is the "eminently portable 'Restaurant Synthesizer'", which will have the potential to bring user programmable sounds to all environments.

Microcomputers relate in two ways to his work. They are "dandy" random number generators, and are able to monitor real time conditions while performing other functions. His current applications of this are in his "continuing research with the I Ching," and in suggesting musical activity derived from slowly changing weather conditions. "Blue" Gene Tyranny has agreed to record a solo keyboard version of this piece, entitled "Weather," on the Lovely Music label.

On the Friday and Saturday nights Behrman performed the same piece, involving microcomputer and live improvising musicians. The latter were Maggi Payne, flute; Erv Denman, homemade electronic bass; and Bonnie Barnett, extended vocal techniques. The piece has been released as On The Other Ocean (Lovely Music, 463 West St., NYC 10014).

The liner notes explain that the piece "is an improvisation for live musicians centered around six pitches which, when they are played, activate electronic pitch-sensing circuits connected to the 'interrupt' line and input ports of a microcomputer. The microcomputer can sense the order and timing in which the six pitches are played and can react by sending harmony-changing messages to two handmade (analog) music synthesizers. The relationship between the two musicians and the computer is an interactive one with the computer changing the electronically-produced harmonies in response to what the musicians play, and the musicians influenced in their improvising by what the computer does."

Saturday night was a stunning presentation, with masterful performances by all three instrumentalists. Maggi Payne, who also plays on the recording, manifested excellent taste in allowing space to the other performers and the electronics. Bonnie Barnett is an advanced practitioner of extended vocal techniques, and a Dutch new music journal "Interface," has published her paper, Aspects of Vocal Multiphonics, which is now available in the US with two accompanying tapes (920 Van Ness No. 2, San Francisco 94109).

Erv Denman's homemade instruments have a sculptural quality about them which make them visually as well as sonically distinguished. On this occasion, his fretless bass (constructed entirely of drift wood found washed up on the mud flats of the San Francisco Bay) was played into a Mutron Dual Phaser and then a mixer. His instruments are currently on display at the San Francisco Art Institute as part of their "Forms of Sound" show.

The entire project was a large success, with the workshops presenting both technical, philosophical/aesthetic, and practical materials; and Behrman and the invited guests were always available for discussions. Most satisfying was the final Saturday concert, which illustrated that this technology can produce art of high quality, and that these composers' theories and premises can be materialized into lush waves of gorgeous sound. -Bob Davis

Typed by Cheryl Vega 5-14-95