The idea behind The Drowsy Chaperone, a mixed box of delights spoofing the 1920s musical comedy genre, is that you get to see the show of your dreams instead of the one you have to see most of the time. “Your” – our – representative in this quest is Man in Chair, whose opening lament of “I hate theatre” sums up the frustration.

Man is Bob Martin, co-author of a surprise Broadway hit that started out as a private party joke in Toronto; not, one has to say, the most promising of premises. Seated to the side of the stage in his cluttered, faintly seedy apartment, the Man reaches for his collection of show albums and plucks out the vinyl cast recording of a fictional 1928 musical, The Drowsy Chaperone. It comes to life in his hands.

Myself, while not exactly having an uncut version of the Oresteia or the omnibus edition of Arnold Wesker at the top of my wish list, would dream of something a little more, well, charming, as well as ecstasy-inducing, as an escape route to Paradise.

Something like last summer’s production of The Boy Friend in Regent’s Park, for instance, itself a pastiche spoof of a 1920s musical comedy but with an energy all of its own and music and lyrics of genuine merit and delight.

Summer Strallen was the definitive Maisie in that production and set my mind wandering wistfully in that direction when she pops up here as Janet Van De Graaff, the stage ingénue who wants to give it all up for marriage. She does so in a show-stopping “Show Off” number which is an amazing compendium of clichés, high kicks, costume changes and disavowals (“I don’t wanna encore no more”).

But the number takes you nowhere. It settles into a camp groove and stays there alongside all the other ingredients: a sultry, Valentino-style lover with a chinchilla quiff who, in Joseph Alessi’s strenuous performance, just misses more than once; a pair of barking gangsters disguised as pastry cooks who sound anything but Runyonesque; a dotty old dowager hostess (Anne Rogers) fussing over the wedding arrangements with her obsequious butler (Nickolas Grace); and a lesbian aviatrix (Enyonam Gbesemete) whose bi-plane serves as a finale vehicle, flying down to Rio.

That climax is interrupted by a power failure in Man’s flat, not all that surprising given the endless stream of colourful designs and costumes – by David Gallo and Gregg Barnes – that tumble with almost indecent profusion through the surprise show. One of the best gags is the false start to Act Two, when a baffling Chinese opera extract (“What is about the Asians that fascinates Caucasians?”) is aborted when Man realises he has pulled out the wrong record sleeve.

And then there is Elaine Paige as the eponymous chaperone to Janet, a dwarfish dipsomaniac with just one big overblown number, “As We Stumble Along.” Paige shows no qualms in sending herself up, and it is good to hear her big chesty voice emanating from her bird-like frame again.

The music and lyrics of Lisa Lambert and Greg Morrison are not good enough to make you forget Cole Porter and Jerome Kern, but they do have their moments in the manically relentless first act finale, “Toledo Surprise,” and a sweet little soft shoe shuffle, “Love is Always Lovely in the End.” Ah well, it’s all fairly enjoyable. But is it the ultimate musical comedy elixir? Dream on.

--Michael Coveney