Like Chekhov's Three Sisters, the Rat Pack - as a group of celebrated Hollywood entertainers that included Frank Sinatra, Sammy Davis Jr and Dean Martin was once famously dubbed - is suddenly travelling in sets.

As if the lavish musical tribute The Rat Pack - Live from Las Vegas, originally at the Haymarket and now at the Strand Theatre, wasn't enough, there's now Rat Pack Confidential newly arrived at the re-opened Whitehall, by way of Nottingham Playhouse and the Bolton Octagon, to spread confusion to all.

It's simple enough, though: if it's the songs you want, scintillatingly rendered against the backdrop of a proper Big Band, head to the Strand. If it's meagre music (performed to the accompaniment of a five piece band) and weak drama instead, then go to the Whitehall.

So while it is usually terrific when regional productions makes their way to the capital, this lazy, hazy biographical 'tribute' show is no recommendation for the kind of work that a strong producing theatre can offer. It may, of course, be a case of offering the public what it wants, and if it wants nothing more than a collection of songs it already mostly knows, tied to sketchy recreations of personalities it is already fascinated by, then Rat Pack Confidential might be just the ticket.

But Paul Sirett's stage filleting of Shawn Levy's biographical book weaves the songs that we've come to hear through such a clunky and unduly chunky collection of contrived scenes that the cumulative effect is more enervating than energising.

Here in the cabaret setting of a reunion concert, complete with tables replacing the front two rows of the stalls seating, we are introduced to them all again, this time with the set completed by the two lesser-known friends: comedian Joey Bishop, who outlived them all and here functions as a kind of narrator/emcee; and British-born actor Peter Lawford, who famously married into the Kennedy clan and co-starred with Sinatra in the original film version of Ocean's Eleven, long before it was remade as a vehicle for George Clooney.

Under the perfunctory direction of Giles Croft, the quintet recreates flashback scenes from their lives together and apart, and performs songs they have sung with varying degrees of success. While Richard Shelton is a dead ringer, both physically and vocally, for a young Sinatra and fortunately has the lion's share of big numbers that includes "Come Fly with Me", "I Get a Kick Out Of You", "Get Happy", "The Lady is a Tramp" and of course "My Way", Paul Sharma's Sammy Davis Jr comes nowhere near to recreating the spirit, never mind the panache, of the original, with a particularly gruesome account of "What Kind of Fool Am I?".

Dean Martin, of course, managed to destroy his songs via the alcoholic fuzz that he usually performed in, and Alex Giannini duly gives the drunken, loutish turn required. There's more colour and shade in Kevin Colson's Joey Bishop and Robin Kingsland's Lawford, but it's no fault of either actor that the brief biographical sketches in the programme are actually more illuminating about their characters than what we see here.

It's an occasion strictly for die-hard fans, but even they might be better off staying at home with their CDs and the book that this show is based on.

- Mark Shenton