Based at the University of Brighton, the weekend-long Soundwaves festival promises "music for all ears". The centrepiece of this year's genre-hopping programme was a complete performance of one of the most extraordinary products of 1960s British experimentalism, Cornelius Cardew's Treatise, shared between members of the London Sinfonietta and the ensemble Apartment House, video artists Simon Pyke and Mikhail Karikis, and the vocalist Micachu.

Treatise consists of 193 pages of minutely detailed and often very beautiful graphic notation. Conventional musical notation is only used occasionally, and Cardew left no instructions as to how the symbols should be interpreted. He did say, though, that any performance should be "a picture of the score, not vice versa", suggesting that the idea of the notation matters more than anything specific it might seem to define, while the sheer elegance of the score arguably makes it as much a visual artwork as the starting point for a musical one.

Musicians usually choose which pages to realise, but Soundwaves aimed for completeness – hence the more or less seamless three-and-a-half-hour relay of performers working their way through all 193 pages, while the audience came and went. There was a bit of everything: straightforward musical interpretations from the Sinfonietta, and Apartment House; something rather more exotic from Micachu; and extra visual layers added by Pyke and Karikis. If Pyke's rather insistent soundtrack of electronic and sampled sounds often seemed wildly at odds with the pages of the score as they rolled past on the video screen, it's in the nature of Cardew's aesthetic that almost anything goes. But Treatise has its own very special artistic integrity and compels a peculiar respect.