Nederlands Dans Theater, Sadler's Wells, LondonSlow Dancing, Trafalgar Square, London

A fiftieth anniversary show by NDT is expert but empty, while an installation at the foot of Nelson's Column is mesmerising

Beauty is truth, a poet once said, but I'm not so sure it is.

At risk of sounding like a jaded critic who it wouldn't hurt to have to buy her own front stalls tickets for a change, one can have a surfeit of beautiful dancing – dancing whose sleek and shiny surface, initially alluring, covers an emotional void.

Nederlands Dans Theater, popularly known as NDT for most of its half-century existence, is a seasoned purveyor of technical wonders. Its dancers, not unreasonably, have been claimed as the best of their kind in the world. So why did I find myself yawning through the first of their two 50th-anniversary programmes at Sadler's Wells?

All three of the pieces played into the company's favourite mood of dark northern angst. Early moments in Johan Inger's Dissolve in This initially looked hopeful – two boys thrashing and wriggling at unfeasible speed like wireworms on a hook; a duet in which a girl fastidiously brushes off caresses, accelerating until the action becomes a frantic habitual tic. That these things happen on a floor ankle-deep in shreds of ash-grey sponge gives everything a silent, stifled aspect.

Too bad the piece goes on to resemble every other piece of Eurodance you've ever seen, sending the entire cast sprinting in a circle (William Forsythe), or playing grandmother's footsteps (Pina Bausch). The worst of it is that the accumulation of obscure actions, and the portentous execution, suggests that they might actually mean something. And they don't.

Whereabouts Unknown, by the feted Jiri Kylian, isn't much more enlightening. Again, big themes are hinted at: pre-history, tribal peoples, mass migration, to a patchwork of 20th-century music, including Charles Ives's The Unanswered Question. But the effect was less than the sum of these parts. I wonder if NDT have considered using live music? Granted, it would mean scaling everything down. But there is a glibness to performing to discs that at present serves this company ill.

Subject to Change, by Paul Lightfoot and Sol Leon and set to Mahler's reworking of Schubert's Death and the Maiden, cried out for that live spark. On a big red mat manipulated by four wiry, sexy, grim reapers, a couple take stock of their mortality, rage against the inevitable, and finally have the rug tugged from under them – simplistic perhaps, but preferable to all that fuzzy existential posturing.

If the fine detail in any dancer's work is sometimes hard to take in by dint of its speed, Slow Dancing, a project by the New York artist David Michalek, sets the story straight in spectacular fashion. Commissioned by Sadler's Wells to create an installation for the Big Dance season currently popping up all over the capital, Michalek invited 50 prominent dancers from around the globe to prepare a five-second sequence that they felt could represent them. Each sequence was then filmed using a high-definition camera recording at 1,000 frames a second (standard video captures 30), then slowed to last eight minutes. The results, shown on three huge screens lodged at the foot of Nelson's Column after dark every night last week, have been mesmerising. This week the project moves indoors, which will be something else again.

At first glance, the three 20ft-high figures appear to be static. But look away and, just like the view from the old rotating restaurant on the Post Office tower, a dramatic shift has occurred. A few well-known movers are de-natured in the process. Bill Forsythe's hyperactive spikiness is smoothed and tamed; Elizabeth Streb, the New York body-slammer, looks merely polite. Other talents, though, become magnified in slo-mo. The filigree of Balanchine muse Allegra Kent's fingers, the extreme curl of Dana Caspersen's pointed foot, the thunderous force of plus-size dancer Alexandra Beller – all present themselves for leisurely scrutiny. There are curiosities too: hip hop on crutches, a naked pregnant bump, sufi whirling. As at any good party, all the world is there.

'Slow Dancing': Village Underground, Shoreditch, London EC2 (0844 412 4300) 13-24 July, entry, except for Saturday evening, is free.

Next Week:

The Russians are coming! Jenny Gilbert hails the Mikhailovsky Ballet as it opens a two-week season at the Coliseum with Swan Lake