Supersonic, Custard Factory, Birmingham <!-- none onestar twostar threestar fourstar fivestar -->

Birmingham's Capsule promoters divide their time between fragmented laptop electronica and adventurously grinding guitar-core. They're interested in the meeting of the two forms. Over three years, their Supersonic weekender has grown in stature. It now sprawls over three stages of the city's Custard Factory arts complex.

The first night was a link-up with House Of God, Birmingham's long-running hard-techno club, but the most interesting sounds were emanating from Capsule's own room. Chris Clark hunched over his equipment, head nodding spasmodically as he sliced up his digital matter, groaning under a sagging bass weight. Brighton's DJ Shitmat solved the problem of how to be entertaining behind a console, clad in a badger mask and panties worn over jeans, heckling the crowd and adopting extreme cannibalisation methods as he rammed death-metal riffing into drum'n'bass shapes. Birmingham's own PCM duo crowned the night, specialising in an insanely sustained dynamism.

Supersonic's second day increased the guitar input on the outside stage. The day's superior act was the US four-piece Battles, driven into involved time-signatures by the precision drumming of John Stanier, formerly of Helmet. The Battles' stringmen have a penchant for making chord shapes with one hand,while their remaining digits pick out matching keyboard parts. The music is ridiculously intricate, but is still invested with searing aggression and power. Dalek sounded muddy and muffled following the pristine onslaught of Battles.

In the more intimate theatre space, Barbara Morgenstern and To Rococo Rot's Robert Lippok produced melodic, gently undulating electronica. Black Galaxy and Kreepa teamed up with a resourceful fusion of guitar, trombone and electronics, the latter duo bringing in a home-made box which produced immediate hands-on noises.

Michael Rother and Dieter Moebius were in of Neu! and Cluster in the Seventies, and promised to be a highlight, but 10 minutes into their set, the festival ended as Birmingham's centre of was evacuated.