Karlheinz Stockhausen - Mixtur (2003) Salzburg Festival. 30 August 2006

By Robert Worby

Stockhausen composed Mixtur in 1964. It is scored for 5 orchestral groups, sine wave oscillators and ring modulators. It is one of the first pieces, if not the first piece, composed for orchestra and live electronics. During the early performances it was discovered that it was extremely difficult to balance the dynamic forces of a full symphony orchestra with the electronics. In 1967 Stockhausen revised the piece and scaled down the orchestral forces and it is this version that has been performed throughout the world since then.

Microphones collect the sounds of each orchestral group – percussion, woodwind, brass, pizzicato strings and arco (bowed) strings – and the mixed signal from each group, apart from the percussion, is fed into a ring-modulator. This is an early analogue device, invented for use in telecommunications, that modulates one signal with another. The sound of the sci-fi robot villains the Daleks is made using a ring-modulator that combines an actors voice with a fixed low frequency sine wave. In Mixtur it is the sound of instruments – solo and in groups – that is modulated by sine waves the frequency of which change, very precisely, to produce the most incredible sounds – sustained metallic swoops, glissandos screeching from the highest high to the lowest low, pulsing signals like a thousand bristling shortwaves or robots trashing a can factory.

It’s difficult to imagine how Stockhausen had the idea to make this piece. How did he know what it would sound like? He might have been able to work occasionally with individual instrumentalists and a ring modulator, experimenting with possibilities and noting the results. And occasionally he may have had two or three musicians in the studio. But it must have been near impossible to imagine a whole orchestra, divided into five groups, four of which are being ring modulated to produce sounds that nobody had heard before …. ever. To put all this together, invent a way of notating it and make it work must have been like flying to the moon. Maybe that era of the late 60s, when people were flying to the moon, was marked by a true pioneering spirit; a time of journeying into unexplored territory. Stockhausen was certainly doing this in music.

The underlying structural principle of the piece was invented by Stockhausen and is known as ‘Moment’ form. The work is made up of individual units which are “self sufficient”, tiny pieces in themselves, which then combine to make the whole work. In Mixtur there are 20 ‘moments’ and there is some flexibility built into their combination. The piece can be played forwards, from moment 1 through to 20, or backwards (retrograde) from 20 to 1 and some moments may be exchanged with others. Within some ‘moments’, of the original piece, orchestral players are obliged to choose exactly what they play from a selection of material written in the part. There are some elements of chance here, there is some indeterminacy. And it is these elements that Stockhausen has revised in this new realization. Mixtur (2003) has no indeterminacy, all the parts are completely written out, the players no longer have any obligation to make choices.

The world premiere of the new version was scheduled to take place at the Slazburg Festival on 30 August, Stockhausen himself was to conduct. As I was traveling to the airport, on my way to Salzburg, I got a phone call to say that Stockhausen was unable to conduct because of an attack of sciatica. He had rehearsed the orchestra in Berlin but conducting in Salzburg was impossible, he couldn’t leave home. Naturally, this was extremely disappointing. A once-in-a-lifetime experience simply evaporated.

Salzburg was grey. The Alps towered above low cloud. Drizzle soaked everything. The concert venue was the ‘Lehrbauhof’ – the Building College – which was miles out of town. Stockhausen had invited me to attend rehearsals so I arrived at the venue in the middle of the morning having trudged through the suburbs in the rain. It was a dull looking place, nestled into the foot of the mountains. Inside, students were building – walls and things. It looked like a tidy building site, not a venue for an orchestral concert. But tucked away from the construction activity was the college hall and here the orchestra were rehearsing, each separate section dressed in bright coloured shirts – the brass in red, woodwind in blue, arco strings in yellow, pizzicato strings in lime green and percussion in a kind of mauve, although the one percussionist wore red. There was no doubting which section was which.

The sound was fantastic. This hall worked very well. Just the right size. I sat in the middle of the auditorium and the balance was wonderful. The electronics and the orchestra made one sound which sat in the room perfectly. I was able to move my head just a fraction and pick out detail from the rear speakers. If I focused towards the front the rears melded into the mix. All very clear. Rehearsals finished at lunchtime and I took the bus back into town.

I arrived early for the concert. Festival stewards dressed in dark coats with polished brass buttons looked like toytown railway porters but they gave the occasion an air of solemnity. The audience looked like aging professors, or would be aging professors, with their wives dressed straight out of Country Casuals. These were the good burghers of Salzburg and what they liked was Mozart and plenty of it.

The forwards version – ‘Vorwärtsversion – was played first. Extremely precise. Very clear defined pauses between some ‘moments’. This was something new because the 1967 score clearly states “without pauses between the moments”. The balance and the sound were as they had been in rehearsal, absolutely perfect. These players knew exactly what they were doing. This is what comes of six 3 hour rehearsals. In Brtain an orchestra would be lucky to get two rehearsals. The final note, a high C, (‘moment’ 20 is called ‘High C’) was held and held and held, ring modulated sidebands swirling and swirling. And then there was silence. The aging professors didn’t know what to do. What on earth was that? Had the piece finished? Do we applaud? The silence stretched out. I began applauding enthusiastically. Several claps echoed around before the audience sluggishly joined in.

A few polite, wide-eyed socialites gathered around the mixing desk in the interval, asking questions, desperate to make sense of what they'd just heard. Music from outer-space madam, and right here is the spaceship! After the interval we heard the backwards version - ‘Rückwärtsversion. Again, every sound was in its right place, the timbres rich and deep. Rounded basses and hard rattling bassoons, glissandos that felt like they had just swooped off the Alps, electronics like signals from a radio telescope jammed on an alien life form. The applause was a little more confident. The professors’ bewilderment had been temporarily suspended.

When I stepped outside the rain had stopped. On the last bus back into town no one spoke. We rattled through the suburbs, big wooden houses set in their own grounds. The driver squeezed us through a tiny gap in the ancient city walls, back into the land of powdered wigs and red velvet. I wondered what the other passengers were thinking. Maybe one or two of them had secretly enjoyed it, but no doubt most of them would be returning home to tuck up in bed with a nice cup of cocoa and their Mozart teddy bear. Safe and sound. But please, not for them, the sound of today’s music.

© Robert Worby 2006

Robert Worby is a composer, writer and broadcaster.

This article was first published in ‘Diffusion’, the magazine of Sonic Arts Network