After a wait of just over five years, Ragtime has arrived in London at last, but the emperor is wearing new clothes - literally so. Next to the impossibly lavish, cinematic sweep of the 1998 Broadway production, this nakedly staged new version (pumped up from a one-night concert staging at last year's inaugural Cardiff International Festival of Musical Theatre) strips the show back to its words, music and performances. In the leaner, starker, more rudimentary staging that necessarily follows, both the defining strengths - and some of the weaknesses - are exposed.

On the one hand, how wonderful it is to witness a musical that actually seeks to say something, even if it tries to say too much. And though Ragtime wears its heart on its sleeve quite unashamedly, it's also thrilling to hear the kind of emotion-laden music that just isn't written anymore in the post-Sondheim acerbic age. Stephen Flaherty's frequently gorgeous melodies - with Lynn Ahrens' lyrics sung to the rafters by a fiercely committed cast - simply wrap themselves around the theatre.

But without the sets to distract you, there's also too much time to focus on the dense earnestness of some of the storytelling, the contrived links between the stories it tells, and writing that can seem inflated by a sense of self-importance.

Set at the dawning of the last century, Ragtime seems like a last hurrah for old-style Broadway musicals that - from Show Boat and Porgy and Bess to Oklahoma! - have provided a soundtrack for the gritty historical pulse of American life. By contrast, modern counterparts - from West Side Story to Company and Rent - tend to inhabit contemporary urban landscapes.

Terrence McNally's book, based on EL Doctorow's epic novel, concentrates on three American families in 1902 New Rochelle, just outside New York City. There are the WASPs, simply defined as Mother (Maria Friedman), Father (Dave Willetts), their son Little Boy and mother's Younger Brother (Matthew White). There's a Jewish immigrant Tateh (Graham Bickley) and his daughter, Little Girl.

And finally, there's the young black couple, Sarah (Emma Jay Thomas, whose abandoned baby Mother finds in her garden, and Coalhouse Walker Jr (Kevyn Morrow), whose crusade for justice in a racially intolerant world, in which he loses first his car and then Sarah, propels the story. Around them, there are also real-life characters like magician Harry Houdini (Samuel James), vaudeville star Evelyn Nesbit (Rebecca Thornhill), black leader Booker T Washington (David Durham) and workers' rights revolutionary Emma Goldman (Susie McKenna).

Even if the show's ambition and scope don't quite now match its reach in Stafford Arima's extremely well-drilled production, it is beautifully performed by one of the best ensembles in the West End. It deserves to be seen for them and the music.

- Mark Shenton