Rolf Gehlhaar Interview

by Oliver Lowenstein.

fourthdoor@pavilion.co.uk

"The reason I made the whole thing at all to start with, was that I wanted to make a composition that was performed by the audience rather than by performers - for an audience." Rolf Gehlhaar is sitting in the reception foyer of the recently opened new building of the South London Community music centre, Musicworks. He's onto his third coffee and talking about the life history (so far) of a piece of music technology which has absorbed much of his last fifteen years: 'Sound-Spaces'. The nearest to hand version is in situ up a flight of stairs, along a corridor and domiciled in the building's Cornelius Cardew room.

Gehlhaar's 'Sound-Spaces' is maybe the most focused attempt yet to integrate computer technology for making 'hands-off' musical spaces. In effect, 'Sound-Spaces' works by linking up specialised computer technology with ultrasonic sensors that pick up movement occuring within a 3d space, then feeding the shape of those movements back to a computer programme. The (already written) programme generates sounds determined by the person's movements. Any person can enter the 'Sound-Space' and move, dance, and sculpt 'hands-off' sound without needing the skills associated with playing 'hands-on' instruments. People who hitherto needed specialised bodily dexterity to create and make music, are able to make sound and music through their movements. The 'Sound-Space' is also an innovative space for other musicians, particularly though, in collaboration, with dancers.

Whilst Theremin's have reinstated a local micro space version of this - you move your hands around the Theremin's limited spatial range - 'Sound-Spaces' expands the range so the whole body becomes an instrument, with movements sculpting or dancing sounds and music into being.

In so doing, communities which maybe aren't obvious music players, from audiences to dancers (and audiences dancing), children and the disability world, are introduced into the possibilities of on the spot improvisational sound creation. Gehlhaar works intensively with children and adults with learning disabilities. 'Sound-Spaces' though is broader evidence of how this trajectory of New Media, can bring experiences of improvisation and musical creation to otherwise excluded groups. It's technological peers are perhaps Todd Machover's MIT audience activated 'Brain Opera' technology, Copenhagen's Sound Gallery, and on a smaller scale Julie Wilson-Bokowiec and Mark Bromwich's Electronic Dance 'Bodycoder'.

That said, there's clearly no reason why musicians, including your average electronic sound scaper, shouldn't contemplate it's prospective integration into their scheme of things, performances included.

Gehlhaar is a veteran of the sixties electronic music scene. From Germany, he played a central part at Stockhausen's Darmstadt school. In time he became Stockhausen's personal secretary. He's been involved on the edges of the music-technology interface ever since, and has developed a variety of one-off technological innovations. 'Sound-Spaces' seems to be the one he's gone furthest with. Part electronic musician, part innovator-inventer cum gizmo-tinkerer he's been based in London for over two decades refining 'Sound-Spaces', since he first began developing it in the early eighties.

"I had the idea in 1984, which had gradually evolved out of my work of using computers to compose instrumental and electronic music which I started in about 1975. By about ten years later I was writing programmes which I was using like instrumental music. I'd write the programme and I'd feed in values to start it off and then interesting things would start coming out and I'd copy it out. And at one point I built some joy sticks for the computer, those things weren't available in those days. So while the computer was calculating the music according to my instructions and the data I had put in, I could interfere and change those values, using the joysticks, but still I couldn't hear what was going on. It was all coming out in notes on the screen. I had written a programme which printed the notes. At some point I just had the idea that anybody would enjoy doing it. You could have a programme which would calculate some music and then you could influence it as well. I put that idea together. I already had quite a bit of experience putting Interactive stuff together".

"I'd started around 1971 making electronic environments. They were interesting but they were haphazard. You could influence things, but you couldn't control them. So I put the idea together. I then thought about how I was going to make this interactive system, how to track the movement into measurements. I had some experience with infrared and photocells. They were all useless though. I didn't want anything that you had to touch and I wanted something that was precise - that was important. You couldn't make any really good statistical, probability calculations unless you had some precise values. And then I saw that Polaroid had just come out with a camera that used an ultrasonic ranging unit for the Autofocus. So I got in touch with them - that they would sell the individual devices. That was just the transducer and the circuitry that would generate the sound. So I got hold of those and I saw that that would work. Then I made a design of a system of what it would look like, and what it would be able to do. And I sent that proposal to IRCAM in Paris where I'd worked and done some research before, I was known there and they were quite keen on it and they put me in touch with La Villette (the Technology Centre on the outskirts of Paris) which was opening in 1985. They were looking for an exhibit and they commissioned me to make one. I made that with a friend who had a small electronic studio in Southern France. It was exhibited at the Centre Pompidou. There was a big exhibition in '85, called Les Immatterial, organised by a French Philosopher (Jean Francois Lyotard). It was a Postmodern exhibition, a bit drab, the Sound-Space was the most joyful, sparkling thing in the whole exhibition. People just wandered into the Sound-Space, and it got a fantastic response. After a few weeks, people came just for the 'Sound-Space'. It was pretty good though not as good as it is now, technically speaking. It was then installed in the museum. Unfortunately the space there was much smaller than I'd been promised".

Gehlhaar has thoroughly integrated 'Sound-Spaces' into his own music and composition. He recalls one specific example:

"There's a CD of London composers, which has a piece where I perform with the Sound-Space with electronic tape. The first piece I did was with a trombone and two clarinets. It was performed in the dark. It had projections of pictures taken by telescopes, nebulae and stars. The performers were all dressed in black and had little lights on their arms and there were the moving stars in the projections. And I had these pendula across the space which performed as well, so that when the musician finished playing they set off one of three pendula, so that when they stopped that was the end of the piece. It was quite nice".

Gehlhaar says he got into music because of electronics. He'd been at University studying electronics and physics, but found the sixties science environment completely uninspiring.

"I'm very lucky that I had such broad interests when I was young, that I studied physics and electronics and computers and so on. I was actually heading into the sciences, probably something medical. When I was about twenty I discovered that everybody else who was heading in the same direction was actually terribly boring. They knew nothing about music, nothing about art or architecture. I began to think do I want to spend the rest of my life working with people like this, and I said 'no'. When I was at college anybody who I met and found, interesting as a person, was not in science. The scientists were interesting for the knowledge they had about science, but that was it. So boring."

"You still can't make a living with electronic instruments or contemporary serious electronic music. You can't do it. People don't listen to electronic music, because it's not performed. I very soon realised what I needed to do was either live electronics, or to do environments, so I started to do virtual environments in 1971. They were cybernetic in the sense that people did have influence over what was going on. There were little electronic logic devices that would respond to the acoustics and to some kind of input which could be human or could be acoustic inputs. There was a second part to that which was also part of the zeitgeist, which invaded the instrumental musical world, which were called in Germany, 'Wandelkonzert', where the audience was mobile".

Between University and Gehlhaar's specific exploration of designing environments, he linked up with Stockhausen at the time of full flow at Darmstadt. The evolution through to Sound-Spaces is pretty clear; the commitment to electronics, to a revolution in the application of acoustics, and to audience-led interaction continues in Sound-Spaces. "It's completely integral" states Gehlhaar "and a very natural progression. In 1968 I participated in a group composition in Darmstadt with Stockhausen in which twelve composers wrote the music which was performed by twelve interlocking interacting soloists, four trios, etc, where there was improvisation involved and the audience moved through the space. The next year we did something similar in which seven or eight small ensembles played in seven or eight different rooms in a large building and the rooms were connected with PA systems. You could hear any of the rooms in any of the rooms and the audience moved through the building. It was, as you say, part of the artistic zeitgeist. A couple of years later I was commissioned by a German radio station to write a piece for a symphony orchestra, where that was part of the principle, where the orchestra was spread out into four or five different spaces of the concert hall they had, and make a piece of music that would work. And two years later, I was commissioned by a radio station in Germany to write a piece which would redefine the role of the orchestra. So I took the orchestra completely apart and set up a 72 person orchestra around the perimeter of a very large hall, in a circle, divided them up into eight ensembles so they were all set up in the circle. There was no conductor, they conducted themselves visually and acoustically. Everybody could see everybody, everybody could hear everybody. And the audience sat in the middle and made it the perfect ambisonic space".

"I think people will look back and say, 'Jesus, they did some interesting work'. If you look back now to the early synthesisers in electronic music, thirty years ago. They were analogue, there isn't so much you can do with it, but they're so much easier and quicker than digital. And you say they were pretty good, what they were doing with it. Have you listened to Stockhausen's Kontackte recently? I advise you to do it. It's incredible what that man was able to do with the primitive equipment he had. He had a vision, And he had an understanding. He belonged to the first generation who had been educated in acoustics. So that with 'Kontackte' the musical vision was related to an understanding of acoustics, so there was also a physical vision, which allowed him to make the music. And that's very important. Composers are much more informed. My generation were basically - in the Western world anyway - the first generation of composers who were all informed, who knew about acoustics. It was the physical acoustics which influenced many in what they were doing."

Gehlhaar went on to develop various small scale projects to satisfy his inventor's curiosity. These include Holographic sound and the entertainingly entitled 'Superstring' instrument. The Holographic sound, he still thinks, "...has great possibilities. The idea was to make a sound that had a genuine acoustic perspective. In other words a complex sound that you could resolve by walking around, and in, so that you could hear from different angles and it had different sides and angles and by moving around in the sound, you could generate the music, because of the particular trajectory that you moved in. I made it in 1981. It works on the principle of creating complex standing waves".

"It's another one of those things which is good for twenty people and that's it. They always have to come in small numbers. Okay, I think there's probably a good reason for that. I was never able to develop it in the end because there's a lot of experimenting required because loudspeakers are not made for reading those kind of signals".

He describes the 'Superstring' as "a non-traditional instrument" which made "nice sounds". "They were long, ski length instruments with two amplified harpsichord strings, and they made a low sound about an octave lower than an sitar. I called it the 'Superstring'. You played it by hitting it with a metal bar. It made an amazing sound. Another one of my cottage industries, I used to make and sell them in Germany. I travelled around Koln, including performing in Mental Hospitals, then I exhibited it in a Museum. It was bought by a German Cosmic rock band".

He searches his memory but can't recall their name. It's clear his heart is elsewhere, stretching way outside the remit of the music world, electronic or rock'n'roll. Modified versions of 'Sound-Spaces' have engaged him since the early eighties, and particularly it's primary, remedial value was initially surprising for Gehlhaar for working with and drawing out elements of the inner adventure of Autistic and other people with severe learning disabilities.

'Sound-Spaces' is part of the repertoire of new musical technologies which can be applied to many different contexts. The ground-rules of what instruments are about, how they could be used, are torn up. An element of this is sounds' inroads into integrating with environmental and urban design, a part of a smart architecture, in public spaces, etc.

"It will, but sometimes I despair. I've always wanted to do something like that. I've been in touch with so many architects who are interested in spatial sound and building, but I've never yet broken through to anyone. They either don't have any money, or they don't see it. Very few people actually have vision at all. It's quite surprising. As for public spaces, yeah, it's easy, and not only sending out information. You could have a speaking clock that when you walk past it, it tells you the time".

Thus any prospective public (or private) space, (preferably with optimum physical dimensions) could be used to create sound. In contrast to much of the digital domain's immediate consequences Gehlhaar's application of digital returns people to the body. This is part of his reservation about music becoming virtual, music over the internet, etc. Virtualisation redefines and defuses musics' power for personal and social interaction. Various observers state the reconnecting with the body implicit in 'Sound-Spaces', and their hybrid kith is the (or a) next stage on the sonic digital frontier. Maybe, but music writers could well be looking back in fifty years amused at the naivety of pre-millenial techno-pronouncements. "It'll be early days for a long time", observes Gehlhaar on the long view of digitalisation's permanent revolution.

"This kind of technology before digital didn't exist", he continues returning to the evolution of 'Sound-Spaces'. "At that time, in 1987, the Sound-Space system was an integrated unit within a computer that had as a part of it an integral synthesiser. It was all-one system. And by 1988, MIDI synthesisers were on the market. I saw the development of MIDI only positively, as a relatively cheap way of universal access to all kinds of sounds".

"Before digital you had influence but didn't have control. It's not until you get to digital that you get control. So from 1988 I started redeveloping the system. The evolution has also been technologically influenced because it's only in the last three years that I've been working with a sampler. As soon as I got a sampler, I started using text . I wrote a number of programmes which just had text in them and I started working with kids where I used environmental rather than musical sounds, and words which might be descriptive of the environmental sounds. That was very interesting. It was a great advance really, because it adds a new dimension to the Sound-Space, of being a kind of virtual environment, rather than being a musical instrument. When I first started doing it, the concept was that it was a musical instrument. At the beginning I never conceived of the Sound-Space being a didactic space and actually I still don't. It's a creative space. What I try to do is not so much teach people something, I don't try to teach them control over something. I prefer them to forget that those ranging limits are there at all. If possible I'd really like to hide them, make them invisible. I want to develop the idea that you can inhabit that space, and it will respond to you're being in it, and that it will respond in fairly complex ways. The more complex its response the more interesting it is to me. It will respond basically predictably, but not always. It just doesn't always respond in the same way because it's a complex space, and the programming itself has characteristics which are not predictable, within a very small frame. Within a large frame it's all predictable. There are probabilities. It works on probabilities, not on fixed quantities, but that's what makes it interesting".

"Computers are speeding up, and that's the most important thing in the last thirty years, because if you want to do things which are really sophisticated you need fast computers - fast and small. The faster and smaller you get the better, because then we will start getting machines that can think. We're not there yet. If you were to make an analogue between transistors and a neuro-junction in the brain, computers are still a hundred times less dense than the brain. I don't know how long it's going to take, but I don't reckon it's going to be longer than ten years to increase two orders of magnitude. This speeding up will enable the development of software, and also computers that can learn. One of the things that would be very interesting in making music is using algorithms and having a computer that can analyse what it's doing, and be aware of what it's doing, and compose a structure. The software today doesn't know what it's doing, but you could add a feedback so that it was analysing what it was doing and making strategic decisions. Then you'll get something much more interesting. If it analyses and notices that for three minutes all the walking in the room has the same distribution and the same speed it could change some of the priorities. There's actually no limit to the complexity of what we can add to the interest of what we can do. No limit. It's a completely open ended system. It's going to take generations and generations and generations to exhaust those possibilities".

This connects in with Generative Music, the Koan programmes of Tim Cole with its horizons of perpetually mutating music, linked into a future meme culture as promoted by the artificial intelligentsia. "Yeah I know Tim Cole: the Koan music. I spent the day with him in his studio, it's nice. It makes sense, it makes nice music. It depends what you want to do with it -algorithmic music, musical probabilities, and designing a process. Imagine you were given a huge garden and you were to design a brook for it which tumbles over rocks, goes into a pool and then comes crashing down into a waterfall. It's a bit like that. The only restriction on it, though I'm sure it's a limitation which won't last very long, is that it isn't interactive, itl runs by itself. That's okay. But it's more interesting if it's interactive. That's what I'm interested in, interactivity on a large scale, so that 10-20 people can interact.".

Gehlhaar states that he doesn't know anyone who has worked as intensively as he has in this field and who has developed the kind of technology and software to the extent thathe has. "There's quite a lot of work going on now, primarily in the last five or six years. There's been this incredible increase in the operating speed of computers. If you have a computer that runs at 200 megahertz, then you can do video bit mapping and have enough computer time ie, with a camera to do things, make measurements. In fact you could use a three dimensional array of cameras and actually localise the person".

"The best system that I've seen so far was developed about three years ago at the Media Lab at MIT. There's a team there which developed a thing called the P-finder, which is a Video camera that watches the person move. It uses an algorithm to find twelve spots on the human body. It does it basically by calculating the points at maximum curvature, the elbow, your hands, your head, your shoulders and so on. It's fairly responsive to movement, it could locate a person and project a little stick figure at ten times a second. It's still a bit slow, but the future is wide open.".

As for the Media Lab's high profile music technology project, Todd Machover's 'Brain Opera', Gehlhaar is understandably supportive, though a mite reserved: "Some of it was very good, some of it not. Mainly because you don't know until you do it whether it's going to work or not, because you're inventing a new form. It should always be a combination of both, the audience and the musicians. It is made and they make it. You can't have only one because you're creating something new that people don't know what to do with. I think what Todd is doing is very interesting though I would like it to be more compact. I'm not interested in the show so much, I'm interested only in so far that it opens the door to something else".

Which is where 'Sound-Spaces', with the common cause of audience integration, comes in. Each of these hybrid technology experiments are exploring paths for audience interactivity - midwives to possible new genres of music. The technology isn't an end in itself, a point often lost on males immersed in technology, it's how it can be used, the kinds of facilitation it opens up for humans and related species. As Gehlhaar clearly states:

"I'm interested in opening doors. What it boils down to in the end is social interaction. That's a strong interest of mine. I somehow feel that the stronger the social interaction becomes, the stronger the individual power becomes".