How do simple things become complex? This programme by Belgian dance company Rosas and musical ensemble Ictus demonstrates an eloquent answer, through music by Steve Reich and choreography by Anne Teresa De Keersmaeker. It opens with Reich’s Pendulum Music: two microphones, swinging on leads, emit a sound each time they pass over an amplifier. The out-of-phase rhythm and pendulum action — never identical — is strangely hypnotic and the leads look almost like walking legs. It’s a simple setup and we’re shown, step by step, how sound, motion and repetition can generate dazzlingly intricate compositions.
In Reich’s Marimba Phase, the repetitive, doubling-up principle is the same, but now there are two percussionists and more intricate rhythms. The resulting sonic splashes and ripples become ever more complex. Yet we still see how they’re formed. It’s as thrilling as being able to perceive patterns in rain.
Having set out the musical ideas, De Keersmaeker shows how they work with dance. In Fase, her remarkable duet from 1983 to Reich’s Piano Phase, two women employ some basic elements – a swing-armed pivot, an airy tiptoe, a swooshy about-turn – but gradually get out of step. Each casts a double shadow on the backcloth. These merge and separate, creating the illusion of a piece for six not two.
It’s a masterclass in composition and we follow it awestruck before De Keersmaeker moves things to a higher plane. Eight Lines features eight women and a repertoire of casual walks, tumbling runs, propeller spins and frog-hops that are distributed among the group to create a wondrous, many-layered perpetuum mobile. The more vigorous Drumming centres around a long, convoluted solo phrase, elements of which are taken up by the entire ensemble in yet another stunning composition.
In Four Organs, one man orbits the stage in a repeated slow twist while four others reconfigure themselves around him, like broken chords around a shifting root. Although it’s as rigorously crafted as ever, the effect is not as instantly captivating. But that’s a minor quibble in a programme which, over two unbroken hours, consistently commands, challenges, enlightens and uplifts.