With Jude Law's Hamlet opening at the Wyndham's this week, there's no end of talk about great Danes in Theatreland at the moment. So it was quite a relief last night to dive into the cosy Jermyn Street theatre where Forbidden Broadway veteran Christine Pedi is presenting her one-woman show – a tribute to the great women of the modern musical stage.

Pedi, for the uninitiated, is a multi award-winning American actress and musical impressionist who has toured the globe. Luckily for us she's stopped off in London, where, together with pianist, musical director and fellow Forbidden veteran Matthew Ward she rattles off 90 minutes of material she could clearly (and probably does) do in her sleep.

The format is very straightforward. Pedi sings as others (Ethel Merman, Patti LuPone, Bernadette Peters) and as herself, the latter sections - including a soulful variation on Annie's “Tomorrow” - providing a reminder of her vocal talents beyond mere impersonation. But the highlights inevitably come when she pulls out the comedy big guns; Barbara Streisand (who she describes as “the greatest Dame of all”) singing “I've Got a Lovely Bunch of Coconuts” is inspired, equally so her performance of an Abba medley in the guise of Liza Minelli, all croaks and squeaks.

Those with even a scant knowledge of these grande dames will appreciate Pedi's uncanny impersonations (her Joan Rivers finale certainly ends the night on a high). And the choice of songs is deft in that she avoids many of the more predictable show tunes.  But there's a slight air of weariness in her performance which is at times rather sapping – getting muddled with the structure is a sure sign the focus isn't what it once was – detracting from an otherwise thoroughly enjoyable evening of musical mimicry.