''If it moves, it's rude.'' Thus ran the Lord Chamberlain's criterion for the difference between art and obscenity in the days when the old Windmill Theatre was presenting saucy-but-artistic displays of female flesh and ostrich feathers in Soho's answer to the Moulin Rouge. Hardly had the Lord Chamberlain's office shut up shop in the late 1960s than costume budgets were drastically reduced. Hair, Oh Calcutta, Let My People Come. A few good tunes and the words "Contains Nudity" displayed prominently on the posters and you were laughing.

Dance, of course, has always been a bit rude. Ballerinas' skirts grew shorter during the 19th century in order to display the increasingly nimble footwork of the dancers. Men, who were normally lucky to glimpse a shapely ankle, found that the ballet was a respectable excuse for looking at pretty women practically naked from the waist down. Indeed, in America, where matrons were fighting a rearguard action against the bestial squalor and vulgarity of the Wild West, ballet dancing was downright obscene.

The line between high art and low rent may be perfectly clear in the mind of the choreographer and his more enlightened admirers, but there is no escaping the fact that much of the audience will be there for less respectable reasons. Particularly if the body in question is male. Javier de Frutos (right) is known for his naked performances. His most recent work, Grass, is danced to Maria Callas's recording of Madame Butterfly, and is a violent, unsettling piece danced by de Frutos, Pari Nadeiri and Jamie Watton who inhabit a grim world in which the vulnerable human body can be made to shiver with ecstasy or convulse with pain. His sold-out performances attract a lot of unfamiliar faces.

They may not actually have mackintoshes on, but the surprising number of middle-aged gents in the audience do not look like your average contemporary dance fans. Not at first they don't. But de Frutos's gifts may yet persuade them that nudity isn't always rude.

Javier de Frutos kicks off the 'Leap Into Dance' festival, Richmond Theatre, The Green (0181-940 0088) 23 Mar, 7.45pm