No major playwright today so stimulates and challenges minds as Tom Stoppard. His Rock 'n' Roll, winner of this year's Evening Standard best play award, is eloquently holding on in a West End nearly two-thirds submerged in a sea of musicals.

To see again Stoppard's epic of communist politics, protest and significant pop music with Dominic West, Emma Fielding and David Calder in the roles originally taken by Rufus Sewell, Sinead Cusack and Brian Cox, is to be reassured that bracing mental exercise for audiences is still permitted on the commercial London stage.

Nobody interested in the suffering of those caught in 20th-century communism's iron grip will want to miss Rock 'n' Roll. Its producers, Sonia Friedman, National Angels and Tulbart Productions, deserve to be named and praised for taking a West End risk with such a distinctly intellectual play.

Stoppard sets in withering dialectical comparison Calder's far-too strident, declamatory Max - an impenitently communist Cambridge academic - and West's exuberant Jan, a stoic Czech graduate student, sent to the university to study and spy.

Jan, whose passions are stirred by rock music, returns home when the Russians crush the 1968 Czech uprising. Shifting in terse scenes between Cambridge and Czechoslavakia, from the doomed Prague Spring to the Velvet Revolution, Stoppard shows why Jan commits himself, despite prison sentence and loss of serious employment, to the indirect political protest of rock music and a real-life persecuted Czech band, the Plastic People of the Universe.

These Czech musicians; the god Pan, nicely incarnated in enigmatic human form by Jason Courtis; the ancient Greek love poet Sappho as taught by Max's cancer-ridden wife Eleanor; and Syd Barrett, Pink Floyd's lost begetter: all these are linked in a Stoppardian chain of romantic, dissident, anti-political being - poetic antidotes to communism's certainties.

In Trevor Nunn's rather ponderous production, not helped by Robert Jones's dull minimalist settings but powered by the sound of rock'n' roll classics that separate the scenes, West captures the dogged stoicism, vulnerabilities, introversion and charm of Jan: only his continual, almost manic hand-waving distracts.

Emma Fielding's Eleanor achieves a sad, dying fall. She surrenders to overemphatic charm when playing her own daughter, in a second act beset by Cambridge domestic soap-operatics that finally gives way to the apolitical romanticism that Stoppard celebrates alongside rock'n'roll's anarchism.