TUNE in, turn on, and switch off. Suspend your orthodoxies for Heiner Goebbels's anti-dramatic music theatre work, Black on White, rivetingly performed by the 18 virtuoso players of Ensemble Modern last night, and repeated tonight for all who have ears to hear.

Conceived by German composer Heiner Goebbels as a memorial to a colleague, writer and director Heiner Muller, Black on White is a non-narrative, extended series of scenes in which the musicians, and the music they play, are elements in a concrete sculpture.

It is, as its title might imply, monochromatic. There is no conventional memorial; there are no orthodox physical or musical poses struck. The work is almost consciously anti-expressive. It is stark, bold, theatrical gesture. It represents necessarily no more than you see and hear in front of you. There is no accumulation. There is but a single moment of tenderness in the middle where a high romantic voice and its instrumental accompaniment suggest a window into the soul.

But within this framework all hell breaks loose, musically and theatrically. An electronically generated pulse - the pulse of rock - unites much of the material. Over it, a surreal landscape of music and gesture unfolds, from string quartet to screeching free jazz and a roaring derivative of big band jazz, from the evocative sound of a koto (ritualistically assembled onstage) to the exotic percussiveness of Harry Partch.

And meanwhile musicians parade the stage, throw softballs at an amplified thunder sheet, play skittles with trumpet mutes, and make tea. It's as pointless and no more pointless than drumming your fingers, waiting for time to pass. The playing is out of this world; rampagingly virtuosic. See it tonight if you dare.