Rose English is unclassifiable. She combines grand gesture and precise detail to dizzying comic effect. When not performing in other people's work - she stalked glamorously through Richard Jones' notorious Old Vic production of A Flea in Her Ear and (appropriately enough) played The Spirit of Champagne in Die Fledermaus at ENO - she creates theatre that is genuinely unique.

In My Mathematics she performed conjuring tricks in the restrained atmosphere of the Queen Elizabeth Hall. A little unusual, perhaps, but no big deal until you pause to consider her fellow performers - an accordionist and a horse (a real, live stallion). Part-theatre, part-lecture/demonstration, English cajoled and delighted her audience with dramatic disquisitions upon the nature of performance, bafflement, false eyelashes and snacks. Before that, she filled and thrilled the Hackney Empire with her large-scale spectacular Walks on Water.

To use a much derided term, she is probably closest to performance art, a genre with few hits and a terrifying number of misses. The term alone is enough to cause outbreaks of panic among even hardened theatregoers who recall (all too vividly) being poleaxed with boredom, enduring hours of self-expression, unleavened by the virtues of technique, discipline or humour. Fear not, Rose English embodies all three.

Alternately surprising and surprised, she is like a deliciously stern and eccentric governess who accidentally got mixed up in theatre. Tantamount Esperance, complete with illusionists, aerialists and tango dancers, is proof that great British eccentrics didn't die out with Margaret Rutherford.

Tantamount Esperance, part of the Barclays New Stages Festival, Royal Court Theatre, Sloane Square, SW1 to 4 June (071-730 1745)

(Photograph omitted)