Playing music at random

Kat Austen, CultureLab editor

1104463.jpgJohn Matthias and Alexis Kirke perform Cloud Chamber

Who were the greatest composers of all time? I have wrangled many a time over Mozart versus Thom Yorke, Rogers and Hammerstein and Chopin, crossing genres and time.

Something I hadn't considered, until now, was the possibility that I might want to include artificial neural networks on my list. In fact, I've been missing out on quite a few unexpected composers, as I found out earlier this month at the Peninsula Arts Contemporary Music Festival. It wasn't just artificial life that was on the credits for the music played that weekend: one performance was orchestrated by subatomic particles, and another by its very own audience.

Of the performances relying on artificial neural networks, the most pleasurable to listen to wasCortical Songs by John Matthias and Andrew Prior. The performance was a floating, concordant exploration of the soundscape generated by a duet comprised of Matthias's violin playing and the contemporaneous output generated by the processing of his live performance by an artificial neural network. By altering variables, Prior created different moods with which to accompany the violinist's music.

The novelty of this approach lies with its variability - randomness even. While I wonder whether Prior's tinkering with the variables could override any randomness arising from the AI, the beauty of the music was enough to ensure that this question could easily go unanswered.

Matthias's spectacular violin skills were also made use of in a live performance of Cloud Chamber by Alexis Kirke (see video above). With this composition, a cloud chamber - more commonly used to track the path of subatomic particles - controls the show. The movement of the particles dictates the way in which sound waves from Matthais's violin music are "cut" by Kirke's synthesiser. The little sound grains generated are then manipulated and fed back into Matthias's live performance.

The science doesn't stop there though. Kirke has long been fascinated by baryons - composite particles made for three quarks - and decided to map the different compositions of possible observable baryons into different pitches and rhythms. To this he added neutron scattering data from the Rutherford Appleton Laboratory in Oxford. Then began the hard work of mining this vast swathe of data for phrases to use in his composition.

Sometimes jarring and atonal, the piece may not be to everybody's taste, but the story behind its genesis does add an extra dimension that keeps the audience's attention through the more inaccessible passages.

The artificial neural network and the cloud chamber introduce spontaneity and randomness into the performance, but build on pre-composed music. Going one step further, Café Concrete - an experimental sound art and film collective - performed what can loosely be termed an experiment as they jammed in the foyer of the University of Plymouth's Roland Levinsky Building. Their aim was to use their music to manipulate the distribution of their audience.

Performing in the centre of the foyer, hunched over laptops, synthesisers and a box of children's toys, the Café Concrete Researchers struck up what could loosely be described as a tune, while a team of spotters noted down the number of people within pre-determined segments of the floor space. The data was fed into a device which monitored the sounds being played and directed the performance with commands like "lessen the treble" and "tranquilise the bass". The idea is that, as the performance progresses, the monitoring device learns how the distribution of audience correlates to the different musical directions, and then changes them to make people move - a kind of ambulatory feedback loop.

Of course, there are so many confounding factors in a performance like this that no trustworthy data could be expected, but the idea is as entertaining as watching a group of people in lab coats playing with various electronics and toys. However, from my experience it's unlikely that audience-driven composition is going to be snapping at Chopin's heels any time soon.

The author's accommodation at the festival was part funded by the University of Plymouth.