Buckland's objects - a huge ball of light, a tilting screen-cum-roof, and his and Sasha Keir's stilts and arm extensions for a designer scarecrow - together with Barry's music, a series of irresolute passages, cranky and amicable by turns, for piano, cello, violin and viola, do not so much trespass onDavies's choreography as compete against its natural force and inclination. The dance can only increase in speed as it tries to wipe out each intrusion.
As she demonstrated in last year's The Art of Touch, set to Scarlatti's harpsichord sonatas, Davies is entrenched in exploring her dancers' capacity for fast and intricate phrases of movement. But in Trespass the dance appears to be racing against, for instance, the domination of the score's gagged strings and pounding piano. Likewise, Buckland's suspended, rectangular mass seems to dwarf and displace the performers.
The work opens with a slow, meditative phrase in which Gill Clarke and the scarecrow figure hint at the unequal power play yet to occur. Beneath the scarecrow's massive arms, now tracing wide arcs in an assertion of territorial rights to the darkened space, Clarke is rendered insignificant yet not invisible. As the scene fades, other dancers enter along a downstage corridor, shaping their torsos and limbs in a rapid stream of sculptural configurations. But, as the piece proceeds, the dance element frequently allows itself to be overwhelmed. Davies's acceptance that her choreography might be influenced by other elements does not permit wholesale takeover. But despite her associates' rather heavy-handed interpretation, the work emerges as one in which the choreographer, at least, shows us a proper, sustained and riveting act of trespass - that of the dance continuously infiltrating and re-examining its own place of action, unable to leave itself alone as it ripples, surges and back-tracks across the stage.
Composers and choreographers insist that the discrete elements of their collaboration must be able to stand alone. Otherwise, one overshadows, even obliterates, the other. The music frequently does stand alone in the concert hall. The dance, on the other hand, at least at the moment of the audience's perception, always exists in some relationship, however obscure, with its accompaniment. Gerald Barry's music is fidgety, sometimes convulsively so, yet in Siobhan Davies's Trespass it generates movement that is dreamily serene. Even so, there is no sense that the two don't fit.
What Barry provides are two piano quartets, the second, which is new, leading to the first, written in 1992. The music begins as if violin and piano (the players are in the pit) are sizing each other up. Once they establish a relationship, viola and cello join in. There are moments of delirium, others when the music careens back and forth between lilting folkishness and a kind of martial baroque; Davies's choreography usually moves at a tangent, although when the music is at its most frenzied, the dancers seem to provide a cartoon illustration of what we are hearing, and at one moment co-ordination is exact, the music achieving silence as the dancers freeze.
The work's title derives from her wish that music, dance, costume, design and lighting should "trespass on the others' domain". Certainly design is here a significant player. An enigmatic figure, resembling Edward Scissorhands with stretched limbs, hovers over the early movement. Later a radiant globe is rolled around the stage, but although eerie, its presence feels tentative, unresolved.
Still, there is a playful humour in Davies's choreography: she has a way of making mystery out of mere walking and running. This is perhaps where it best matches Barry's music, finding natural poetry in everyday zaniness. That poetry is at its most poignant during the closing moments. As the instruments resolve the tensions that have agitated the music, Peter Mumford's lighting provides a set of feux follets to lead the dancers into darkness. When music and movement have disappeared we are left longing for their return.
31 May and 1 June at the Theatre Royal, Newcastle (0191 232 2061); 4-5 June at the Crucible Theatre, Sheffield (0114- 276 9922)