Few could argue that Stephen Sondheim's Follies is about as magnificent as musicals get.

The story - about a group of ageing showgirls who reunite in the now-dilapidated theatre (about to be turned into a parking lot) where they once performed - is devastatingly poignant and the score that accompanies it incredible. Thirty years ago, best friends and showgirls Sally and Phyllis married Buddy and Ben and, as they return to the theatre where they met, their pasts rise up to confront them at every turn.

Given that there hasn't been a major London production of Follies in 15 years, it's understandable that expectations have been running high for Paul Kerryson's revival.

First impressions are good, thanks to designer Paul Farnsworth's elegant transformation of the Royal Festival Hall. A concert hall isn't geared towards musicals (especially not one that pines so for a theatre), but Farnsworth overcomes all emotional and logistical hurdles with an evocative mess of scaffolding, ragged sheeting and several movable staircases.

Through these tired remains, the ghosts of the showgirls' young selves drift in and out, dressed in diamante-encrusted costumes, topped by peacock headdresses. The disadvantage of such spectacular costumes is that, in several cases here, they outshine the performers they cloak.

In the main leads, opera singer David Durham (a last-minute replacement for Clarke Peters) may wish that the venue was still acting as a concert hall, as his acting ability is simply not up to the demands of the tortured Ben. Likewise, as his wife, Louise Gold never really finds the brittleness of Phyllis, though the Act Two toe-tapper "Story of Lucy and Jessie" does play to her strengths.

In a league apart are Kathryn Evans and Henry Goodman. Evans is a very fine Sally indeed - her "Losing My Mind" aches with desperation that's almost painful to watch. Here's an actress who deserves much wider recognition; why she isn't a bigger West End star is a mystery. Goodman puts his whole broken heart into the role of her rejected Buddy, finding the character's frantically giddy core in "The Right Girl".

In support, Joan Savage is worthy of a special mention for her fantastic, show-stopping rendition of "Broadway Baby".

Sondheim aficionados will likely find fault with Kerryson's somewhat lackadaisical production. (My own niggles centre on the first act, when there's a over-reliance on spotlights and the early snatches of introduction get things off to a cumbersome start.) But those encountering Follies for the first time can't help but be blown away by Sondheim's intensity.

Kerryson may not wholly succeed in revitalising this classic musical, but he doesn't diminish it either. Follies remains a truly remarkable and captivating piece of theatre magic.

- Sarah Beaumont