Our Oceans are Drowning and This is Not A Dance@ Dance Base

Rosalind Masson has dabbled in improvisation and dance on film: for her first Dance Base main programme offering, she has been inspired by environmental devastation. Using plastic cups and minimalist lighting - by turns they become a landscape, a topological map and a vivid symbol of western wastefulness - Masson manages to get across her grave concerns about wasting the wilderness without slipping into blunt preaching.

Masson's style is always elegant: the severity of her message is tempered by the fluidity and finesse of her movement. Harsh sections of the soundtrack - using the sounds of planets, recorded by NASA, as a techno assualt - are matched by frantic, repetitious gestures. Like a re-imagining of voguing as post-modern dance, or a new version of Indian dance's stylised poses, her urgent sequences capture the neurotic activity of a creature preparing to destroy its own home.

The seriousness of Masson's worries does not prevent her from a sly touch of humour. When the soundtrack collects radio reports and extracts from studies on the environment, she undercuts the potential pomposity with a sudden sample from the Wizard of Oz. Dance is revealed as a strong medium for presenting ideas, smooth and engaging while holding the issue at the heart of the show.

Ultimate Dancer laughs at the petty pretentions of "dance". With spit and tongue she licks away the division between dance and not dance. Ultimate Dancer does not fear theory. Ultimate Dancer does not fear hilarity. Ultimate Dancer dares to attack the boundaries between popular and intellectual and respects both Hulk Hogan and Pina Bausch.

The now unfashionable term "contemporary dance" once hid the magic of movement behind mystification. Ultimate Dancer paces and pounces, confuses and enchants, and deconstructs ideas of elegance, discipline and perfection as definitions of dance. Clad in lycra, awkwardly elegant, she quotes pieces of well-known and obscure choreography - even YouTube moments have their place - and asks a simple question: is this dance?

Yet she is never aggressive towards the audience: Ultimate Dancer is having an internal battle, trying to decide at what point her movement becomes dance. She is charming, even when she head-butts the microphone or falls to her knees in apparent supplication to her art.

The mash-up of styles, the determined iconoclasm - big name choreographers are not safe from being absorbed in this Ultimate Dance - and the subversive wit are all signifiers of Ultimate Dancer's post-modern temper. And yet, in seeking to kill ideas about dance in order to allow dance to be born again, Ultimate Dancer is following the most ancient and profound of meta-narratives, acting as a shaman to discover and bring back new knowledge and forge possibilities.