With today's audiences reared on special effects, it must be getting harder to make jaws drop. Circus people do it by making relatively simple stunts look more difficult than they really are. Momentary Fusion, with what they call aerial dance-theatre, take the really daring option: stillness.

Long stretches of their latest show, Stung, seen at Jackson's Lane in north London on Wednesday, seem not so much slow as catatonic. When one frail foot hooked over a trapeze is all that stands between life and a broken neck, to dangle motionless for minutes on end looks not only like nonchalance but theatrical suicide. The fact that the spectators remained not only awake but with their eyes on stalks was one of the marvels of the show.

With trapeze, a hoop, ropes and a swinging lightbulb, the three female performers gently subvert almost every aspect of the traditional flying act. Not afraid to descend from the gods, bodies swirl at the end of ropes like water round a bathplug, skimming an inch above the floor in a perfectly synchronised whorl. Or they oscillate across the stage like shadowy pendulums alternating with the bare bulb on its long flex. Even the leotards express unusually serious intent, tailored grey numbers that might have been made for Mussolini's gym team.

There are drum-rolls, but such as you've never heard before. Neil Conti has played with Annie Lennox and gives this the full rock-gig treatment, announcing his arrival by flinging two dozen drumsticks from the wings, but once installed at his kit, exploring the most delicate possibilities of timbre and touch.

Director and performer Isabel Rocamora's cinematic ideas spawn the most memorable images: three sets of limbs tangling in luscious slow-motion atop a slender hoop; mad, Pierrot Lunaire spasms cut by a freeze-frame of a stricken face, more tragic for being upside-down. Body-shapes are petrified into classic sculptures - I spotted The Three Graces 20 feet up. It makes extraordinary muscular demands, yet there is never a fumbled hold. Technically the work is faultless, but more than halfway through its short 70 minutes it is still not clear how such a show can justify itself as "theatre". And then suddenly it does.

Up on a high trapeze, gaunt-faced Rocamora apparently contemplates a death-leap. By subtle tilts and perilous one-hand grips it's clear she's wavering, toying with the dice. A concealed body-mike relays moans and sighs and the squeak of her hands on the ropes. A fellow performer shins up a rope to help, but rescue is not straightforward. Then follows a riveting study of fear and solitude as the pair engage in ever more complex and risky manoeuvres. Taking intimacy and trust to the limits, they finally arrive at an aesthetically satisfying symmetry, a kind of resolution and redemption. The audience breathes again.

Momentary Fusion deliver an erotic charge far removed from the usual titillation of aerial acts. This could be just the paradox of beauty- page profiles with he-man strength. But it's also the intense grip of female on female, a sisterhood of tactile dependency, that makes you sense there's something else going on up there. Call it what you will, this super-terrestrial dance is heady stuff and wants seeing.

A very different idea of femaleness was on display in the shape of Alarmel Valli, exponent of Bharatanatyam, as the concluding event of the Festival of India's South. Entire extended families ranging from little girls in sparkly dresses to wizened grandmamas in saris scorned South Bank regulations and noisily unwrapped refreshments in the stalls - a pointer to a culture that still sees performance as part of everyday life.

A speciality of the extreme South, Bharatanatyam is an ancient form once performed by girls dedicated to Dravidian temples. To many Indians it has a sacred significance as an art in which the dancer submerges her identity in rhythm to express the nature of the deity. To the non-connoisseur, its idiosyncratic code is made accessible by being based on simple mimed stories. But there's a cultural snag.

Where a native audience applauds the subordination of woman to her god and her man, Westerners bridle. For all Valli's modest attire - complicated wrappings covering everything but ankles and arms - she appears to non- Indians as a gorgeous coquette, her mobile eyebrows and flexible scarlet toes merely exotic substitutes for a beckoning finger. An unnerving resemblance to the young Elizabeth Taylor only compounds the effect. Now I understand why the acclaimed London-based choreographer Shobana Jeyasingh has braved the wrath of traditionalists to adapt the form for modern women. Supplication is no longer a part of the language they speak.

Momentary Fusion: Live Art Festival, Spitalfields Mkt, E1, today; Colchester Arts Ctr (01206 577301), Wed & Thurs.