Mime, as a form of entertainment, has never quite gone away.

As perhaps the oldest form of artistic expression, mime was absorbed into the language of classical ballet and there it got stuck until Marcel Marceau brought it new and vibrant status as an independent theatrical art.

It has fallen to Robert Shields to attempt to bring mime into the mainstream entertainment scene. As the first American to win a scholarship to Marceau's Paris School, he went on to bring mime literally into the streets, working for seven years on the outside stage of the streets of San Francisco.

Almost inevitably, he graduated to television, where his rapid rise to fame was reflected in his own series on CBS and an eventual Emmy Award.

Those early days as a street entertainer were effectively recaptured for the City Hall audience in the opening black and white film sequence. Here were all the ingredients of classic clowning as he slid and slithered with feline grace amongst wary spectators, earning a giggling shove here, a startled brush-off there, and even the occasional indignant swat round the head.

From then on, his solo tour de force onstage took the audience through a bewildering array of moods and themes, the traditional capers of the clown progressing through to some distinctly bizarre gyrations embracing the world of country and western, Michael Jackson, the age of automation, advertising and the reign of the ghetto blaster.

Blessed with a marvellously agile body and expressive face, he was at his best when he allowed us a glimpse of the preoccupied, private world of the classic white-faced, baggy-trousered clown. With a fund of illusory tricks that included grotesquely lengthening arms and feet that seemed to skate instead of walk, he evoked an air of Petrushka-esque pathos.

Outstanding sketches included the "swimming'' sequence, where the motion of his hands brilliantly conveyed the rippling waves of the sea, his portrayal of a "cool guy'' robot, and the closing gravity-fighting pas de deux with a red balloon that was infused with a tender kind of lyricism.

It is perhaps significant that Shields apparently studied only briefly with the great French mime, impatient as he was to bring his version of the art to the masses.

Another Marceau he is not, lacking the extraordinary technique, honed over years of practice that enabled the Frenchman to capture nuances of human behaviour that are universal in appeal. For Robert Shields is an essentially American entertainer, who dabbles for sometimes only seconds at a time in themes that take on a cartoon-like quality, rather like the very TV ads which he himself parodies.

And for this purist, his heavy reliance on sound brings him at times dangerously close to lip-sync rather than mime.

PATRICIA CALNAN CLOWNING MIME -- Robert Shields, one of the world's greatest mimes opened at City Hall last night and continues through Saturday evening. There will be a matinee on Saturday at 2 p.m.