John Doyle’s adaptation of HMS Pinafore is less an upbeat version of Gilbert and Sullivan’s jolly shipboard tale than a stylish salute to the professional entertainers who volunteered to entertain the troops during World War II.

We’re invited aboard the HMS P4, affectionately known as ‘Pinafore’ to meet the ship’s own troupe of musicians. There are knowingly mischievous parallels with the original. The all-girl trio of hot brass players is known as ‘The Butterflies’. Beebee Butterfly (winningly played by Nina Lucking) represents ‘poor little Buttercup’ the bumboat woman who sets the original plot in motion by mixing up two babies. Years ago, this careless child minder swapped a true blue Brit baby boy with (horrors!) an infant Yankee doodle dandy.

Both grow into musicians who find themselves in the same band on the same boat, rivals for the affection of the same girl - the bandleader’s daughter, Jenny the Wren (Gemma Page, neatly turned out and a neat mover too).

Whilst I can’t fault the terrific musicianship of the cast and musical director Sarah Travis’s glorious arrangements, the storytelling tends to ramble. I doubt I’d be able to give this plot summary without knowledge of the original operetta.

And though the production certainly ignites when the guys and gals get to swing on the dance floor in an exhilarating Lindy Hop (choreography by Elizabeth Marsh), these moments don’t happen often enough. And Sarah-Jane McClelland’s attractive art-deco set seems too cramped to allow that swing to get going.

Still, if you take the Butterflies to be a mini tribute band to Ivy Benson’s famous all-girl, orchestra, you’ll appreciate their hot musicianship, the smart angles of their instruments and their dashing glamour. Claire Storey, sporting an eyepatch, makes a mean, swashbuckling Dee Dee Butterfly, and Kerry Jones engages as Hee Hee Butterfly, a blonde bombshell with a heart of gold.

Kieran Buckeridge as the best of British and Ben Tolley as the all-American do just fine as rivals for Jenny’s hand. Stephen Watts adds authority as her father the (Band) Captain, with Steve Simmonds completing the cast – and the musical line-up with great bass playing.

Some of the best musical moments in the show owe little to Gilbert and Sullivan and more to Travis’s tuneful takes on the wartime swing styles made popular by the plucky entertainers to whom this show is an equally plucky, albeit rather sketchy and unfocused, tribute.

- Judi Herman (reviewed at the Watermill Theatre, Newbury)