Savion Glover, Sadler's Wells, London

No question, Savion Glover is a virtuoso. Bare Soundz, the latest show by the world's leading tap-dancer, is a stripped-down display of percussive footwork. There's no band, just Glover and two backing dancers. The steps are fast, hard and astonishingly intricate. Yet the show lacks variety.

Now 34, Glover made his Broadway debut at the age of 10. He has appeared everywhere from hip-hop videos to Sesame Street. He provided the steps for the penguin hero of the animated film Happy Feet.

Bare Soundz is a world away from cartoon penguins. Glover, Marshall Davis Jr and Maurice Chestnut dance on platforms. The design suggests a music gig, with amps and lights on stage. The dancers, together or taking turns, establish a rhythm, elaborate and embroider on it.

That elaboration is at the heart of Bare Soundz. Glover gets every possible sound out of a tap shoe, from the sharp blow of a heel to a long metallic scrape as he drags a foot. He can do both at once, and a dozen other things in the same phrase.

The technique seems limitless, but the material isn't. This show is rarely expansive: Glover will always take a complex rhythm over a bouncy one. For the first numbers, all the interest is from the knees down; an arm may swing, but we're really here for the sound. And it's noticeable that the audience responds most to the visuals: the minute Glover starts bringing his whole body into the dance, the crowd starts cheering.

Later numbers are more fun. "Trading Places" is a lovely shared dance; here, at last, the point is variety, contrast. In a solo, Glover taps out the rhythms of a galloping horse. But he won't move far from complex sound-games. His talent is phenomenal, but it's becoming narrow.