It’s hard to think of a work that sums up the late 1960s in contemporary music more than Stockhausen’s Stimmung. A ritual style of performance in which six singers sit in an illuminated circle on cushions in an otherwise dark auditorium; texts that combine the mundane (the days of the week), incantation (‘magic names’ of deities from around the world) and pornography (erotic poems of the composer’s own devising) – all it seems to lack is the distribution of mind-altering substances. ‘Tune in, turn on, drop out.’

Theatre of Voices © Lars Bjarnø
Theatre of Voices
© Lars Bjarnø

This year, which would have been Stockhausen’s 90th, marks the 50th anniversary of its première. With much of the performance detail left to the individual musicians, various vocal ensembles have made the work their own in the intervening decades, and Theatre of Voices under the artistic direction of Paul Hillier crafted their own take on Stimmung in 2006, the so-called ‘Copenhagen version’. It was this same group and this version that combined for this 50th-birthday performance as part of Kings Place’s fascinating ‘Time Unwrapped’ season.

Musically, it’s one of Stockhausen’s most approachable works: it uses just six sung notes, half a dozen of the upper partials or overtones of an unheard low B flat, with each singer – three male, three female – ‘owning’ one of the notes in this harmonious, extended chord (in technical terms a chord of the 9th). The composer’s trick is to ask the singers to use their vocal cavities and articulation to change the overtones of these sung notes. The group’s tenor Wolodymyr Smishkewych introduced us to this concept, complete with audience participation, in advance of the performance proper – how different upper partials effectively emerge by varying the vowel sound in a single sung note. Or as he suggested, slowly articulate the metamorphosing vowel sounds in the word ‘weird’ across the same note sung in a nasal American drawl and listen to the changing ‘harmonies’ it produces. It was a property of the human voice that Stockhausen apparently first gleaned from the humming of his new-born baby.

Stimmung is a piece that probably works best performed in the round, with the circle of singers in the middle of the audience, but Kings Place’s raised stage, with the singers of Theatre of Voices perched around a low table and a glowing ‘moon’ at its centre, proved to be contained enough to draw the ear and eye to the focus of attention. More than once in his introduction, Smishkewych described what we were about to hear as a 70-minute meditation, but performing it must change the concept of time since the result drifted close to an hour and a half. Ninety or so minutes of a six-note chord, broken apart and put back together in different combinations and with an ever-the-same, always changing palette of colours. The work seems to thrive on oxymoron and contradiction, and the focus of the singers’ performance drew us in to Stockhausen’s world: time stood still yet flew by.

Fortunately, for all the composer’s lofty disdain of real life in what might be termed his later megalomaniac phase, Stimmung is not a piece that takes itself completely seriously, and there’s enough wit to leaven the hallowed fragrance it might give off – the measured, po-faced intonation of some of the erotic texts, the sudden eruption of the word ‘barbershop’ on a suitably close-harmony version of the chord, for instance. And the collaborative interaction between the six singers intoning into their microphones as they passed the ‘baton’ of direction between each other revealed a sensitivity and enjoyment of the process of performance that transmitted to us in the audience.

There’s a danger with pieces such as this that its pretensions and idiosyncrasies make it too much a product of its own era to communicate across the decades to these more cynical times, but Theatre of Voices proved here that the potency of 1968, however distant or absent from personal memory, can still communicate, even intoxicate, five decades on.