Treading the fine line between homage and parody is tough. Doing it through the notoriously tricky medium of the new musical - where successful too often means it's a revival or a 'jukebox' musical - is even tougher.

Sad to say, but this musical from Tony Award-winning lyricist and librettist Lynne Ahrens and Ragtime composer Stephen Flaherty really struggles. It was nominated for a Drama Desk Award for its Off-Broadway stint in 2007 but it's hard to work out why.

Adapted from a novel, The Glorious Ones is roughly based around the historical figures who were at the forefront of Commedia dell'arte, with a few of its trademark stock characters and masks chucked in for good measure. Unfortunately its shallow plot line runs like a one-dimensional Disney movie but with none of the catchy tunes to lift its scatty narrative.

The book is boring, the lyrics lazy ("It's a comedy!") or worse, saccharine ("He fell in my moonlit gaze") which is almost depressing when there's such talent on display from a fine cast.

Crisp, clear musical direction from Joanna Cichonska can't save the dull score.

Special mention must go to a strong vocal performance from Kate Brennan, the feisty, reformed courtesan who falls in love with leader of roaming acting troupe Flaminio, played by Mike Christie (one quarter of platinum-selling 'popera' group G4).

The Landor shows off top production values - it looks good, with great period costumes and simple staging. After the recent success with the Ragtime revival, director Robert McWhir probably hoped for another Off-West End mini-hit.

But smattering some of the numbers with crude sexual thrusting - in the recurring play-within-the-play device - only misses the rough bawdy humour aimed at, instead verging on the bizarre.

It's always a shame to see a half empty theatre, especially at a venue as decent as the small but perfectly formed Landor, but in this case you can't help feeling it's warranted. You also stop to wonder what on earth the Yanks were thinking.

- Vicky Ellis