"...an almost magical experience, as Gehlhaar conjures a music of both graceful and robust beauty out of thin air." Rolf Gehlhaar
RECORDED MUSIC
performing on amplified percussion with the SOUND=SPACE System
approximately 70 minutes of ambisonic music
for further information, please email me: gehlhaar@bigfoot.com
Some notes on the programme:
Since 1986 I have been working with a real-time remote gestural control system for synthesisers which I designed and developed in 1984/85. This system, comprised of an ultrasonic echo-location system linked to a computer running real-time sound synthesiser or sampler control and composition software, has been used in many different applications, all of which I refer to as SOUND=SPACE.
I use this system as my instrument for all of the pieces in this concert. The electronic sounds which I create are triggered and controlled entirely by my movements, the position and displacement of my hands and body being measured by the ranging devices and thereby functioning as real-time control values for a computer programme that constructs musical events and generates the commands required by the synthesisers or samplers in order to generate sounds.
Essentially, CUSPS, SWALLOWTAILS, ORBITS and BUTTERFLIES is a single composition in four parts. The titles of three of the pieces are taken from a branch of modern mathematics - Catastrophe Theory - and are the names given to the main types of sudden, discontinuous transitions that may take place in dynamic systems which have more than one stable state. These types of abrupt transitions are reflected in the musical processes - increasingly complex and bifurcated - and physical gestures involved in the performance of the individual pieces. The computer plays a central role in more than one way: not only does it process the measurements made by the ranging system, functioning as the main metronome and control network for triggering the sounds, but it also composes sound structures under my direct influence, interpreting the measurements caused by my movement.
CUSPS combines an earlier composition for 4-channel electronic sounds on tape (SUB ROSA produced in the studio of the CERM, Metz, in 1980) with a live supporting commentary. In its course I explore the peculiarly rich and cavernous soundworld of the taped part whose sounds themselves were discovered within dense electronic noises. These were processed and reprocessed many times, employing the techniques of multiple superposition and variable phase shifting (flanging) to such an extent that new sound events, which seem previously to have been hidden, emerge and take wing.
SWALLOWTAILS employs an active branch of the SOUND=SPACE software. While I am playing the amplified cymbals, the activity of my arms - each arm is measured individually - controls a simple process of composition by the computer. In effect, I am 'conducting' a somewhat emancipated, improvising 'ensemble': I have precise control over when the ensemble plays, and, from moment to moment, fairly precise control over how long it will continue to play, how many of its instruments are playing, how fast it plays, in which general register (high-low) and how loud. Due to special playing techniques and the extremely close positioning of the microphones to the surface of the cymbals, a wide variety of sounds not normally associated with them become audible. Most of the time the cymbals serve as metallic resonators which respond, each with its own characteristic spectrum, to the wide variety of materials with which I scrape, stroke, strike or scare them.
ORBITS also combines an earlier composition for 4-channel electronic sounds on tape (No. 3 of the 5 GERMAN DANCES produced in the Studio for Electronic Music of the WDR, Cologne, in 1975). This tape composition is primarily concerned with the behaviour and movement of sounds as if they were particles in motion, emitting sound. In this performance, the live sounds generally either remain fixed in place, being surrounded by the sounds on tape, or they pursue the sounds on tape, moving in vast elliptical orbits, sometimes disappearing over one horizon, only to reappear again on another.
BUTTERFLIES, the most complex yet transparent of the pieces, is played entirely by sounds produced by the sampler/synthesisers. At its heart lie sequences of movements derived from plotted images generated with fractal mathematics, the mathematics that makes it possible to develop computer programmes which, on the basis of simple recursive formulae, can create images of fantastic beauty, often strikingly similar to organic structures such as leafy branches, fern leaves, shells, grasses and even broken, twisting mountainous landscapes.
(An ambisonically encoded recording of CUSPS has been issued on CD:
Paradigm PD05 : Variations 2: A London Compilation)
