The Critics: Lindsay Kemp conjures a lurid array of underworld characters of deliciously uncertain sexuality
Take A clutch of handsome dancers, set them on a glaring red floor next to three loud African drums, ignite and stand well clear. What do you get? Nothing very exciting, in the case of Richard Alston's latest dancework, Okho. The Queen Elizabeth Hall was full on Thursday, anticipating fireworks from two scores for percussion by the Greek avant-gardist Iannis Xenakis. But the mixed crowd of new-music and dance fans came away unconvinced by the marriage of their disciplines. Alston's work, while beautifully crafted, is no match for the roughcast vigour of Xenakis. For this is music that, once having set out its worktop, empties the kitchen cupboards and bashes the lot to bits.

The venue is partly to blame. The open-plan stage of the QEH belittles the dancers' most volcanic muscular efforts, and even from the best seats the audience feels distant and unengaged. Possibly Richard Alston likes it that way. For him, dance is about motion in time and space, not human drama and connection. In Okho, as the drums set up a relentless pulse, five men in earth-brown singlets display their masculine strengths in stretched-out, athletic shapes - hand-springing and swivelling into long, arching phrases. The sense of drummed ritual, progressing through scratchy tremolos to severe fragmentation, is echoed in the warrior-like stance of the dancers. Yet for all its beauty, the chorus movement is wanting in clean synchronisation and virile attack. Perhaps you can't have both, but better one than neither.

When the women take over to dance Xenakis's Psappha, a meditation on the theme of Sappho, antique poetess, the most effective moments are danced in silence. Soloist Angela Towler's pristine line in fluid, back-bending shapes quietly draws all eyes to her and seems to still time, though she herself is never still. More rewarding overall is an earlier piece, Orpheus Singing and Dreaming, in which Orpheus's fatal backward glance is replayed in different ways, building layers of tortured feeling that burst like a dam when the dead Orpheus is finally borne away on a river. Dar- shan Singh Bhuller in bodypaint, and Samantha Smith in an as-tonishing rubber mini-dress (the skin of a snake perhaps?) make compelling drama with the subtlest of means. Richard Alston should give in to basic instinct more often. We love a good story well told.

Lindsay Kemp's wayward theatrical genius may not seem a natural subject for a dance column, but his new show, Variete, defies all attempts at pigeonholing. It might be called opera - for its continuous score by Carlos Miranda - or a musical, for its Brechtian balladeering style. But at its centre is the radiant, gnomic figure of Kemp himself, who neither sings nor speaks, yet imbues the show with an ineffable piquancy that springs from muscular control.

The story is loosely that of Woyzeck, a simple tale of a nobody who falls in love, then, disillusioned, commits the ultimate crime passionnel under a blood-red moon. From a grainy, 1930s fairground set, Kemp conjures a lurid array of underworld characters of deliciously uncertain sexuality. There's the beery, sadistic showman, his suspiciously masculine wife, a werewolf for a son and a deaf-mute trapezist for a daughter, plus sundry pretty boys who (all praise to Kemp for finding them) can sing, act, dance and walk on their hands like a dream. The sight of Kemp dressed as a fluffy chick, faking a high-wire act, is as pathetic as it is hilarious. And Kemp swinging from the hangman's rope (the birdman flies at last) is as grimly cathartic as anything done by the Greeks. Here is an artist who lives and works abroad because he feels unloved here. Variete will surely keep a place warm for him.

The Natural History Museum is not somewhere you expect to find swarming with dancers after closing time, but Genesis Canyon, the work commissioned to open this year's Dance Umbrella, was designed to confound expectations. Who'd ever think that an audience would happily stand for an hour at the foot of a roped-off staircase, gazing at shadows on the ceiling?

American choreographer Steph-an Koplowitz specialises in large-scale happenings in offbeat urban spaces, but his choreography is not in itself ambitious. Here 40 dancers sprawl and sway like fronds on an ocean bed, or roll down the steps like waves of lava. Craig Givens' crinkle-fabric costumes mutate from earth tones to pastels, suggesting sea, then rocks, then flesh. The soundtrack is a primal stew of electronics and tribal chorales, pepped up by a crafty piece of music theatre.

Wandering through the action, as if on a tour of inspection, come three stiffly dressed Victorian dignitaries (singers Sarah-Jane Morris, and the brothers Jonathan and Barnaby Stone) engaged in a vigorous debate in the form of an a cappella trio. Their earnestness is comic, the lyrics Latinate nonsense, but it's not difficult to guess the gist of their argument: the origin of species.

Just to stand in that great terracotta cathedral of science - dramatically lit to accentuate its gothic galleries and buttresses - is to ponder the sweep of human history, the pride of 19th-century scholarship, and the cataclys- mic effect of Darwin's theories on every educated man and woman on the planet. "Site- specific" is a term too often used to cover lack of inspiration. In Genesis Canyon, Koplowitz delivers not great dance, but a multi-layered experience of a great British institution. He puts the muse back into museum.

Richard Alston Co: QEH, SE1 (0171 960 4242), tonight; Epsom Playhouse (01372 742525), Tues & Wed; then touring. Lindsay Kemp: Poole Arts Centre (01202 685222), Mon-Sat; then touring.