Damian Humbley and Sophie-Louise Dann
Damian Humbley and Sophie-Louise Dann
© Alastair Muir

A new edition of Forbidden Broadway, written and directed these past thirty years by Gerard Alessandrini and Philip George, is a welcome blast of musical theatre hilarity, still funny spoofing the Act One finale of Les Misérables on a tiny pretend revolve with a boastful threat of "Ten More Years."

Actually, as the brilliant Damian Humbley is in the cast alongside Sophie-Louise Dann, Anna-Jane Casey and Ben Lewis, it's funnier than ever. And Humbley's hilarious, too, as Ho Chi Minh Cameron, the producer turned Engineer in a bad wig and satin tux, yanking up the ante so the "Americans cream"… there's a toy helicopter, too, and a pair of confused GIs ("The heat is on in Saigon; is there a tune going on?")

There's a wonderful new opening, setting "Rose's Turn" from Gypsy to phone texts and tweets ("Everyone thinks they're a critic") and then the Guys and Dolls fugue as a canon for ticket touts ("I got the show right here") leading to an exposé of child labour in Matilda and Billy Elliot, Humbley sporting sandbag bazookas as Miss Trunchbull.

It was never a commercial runner in London: the show's unashamedly aimed at musical theatre insiders and nuts who adore Broadway; you know who you are. We've not even seen Hugh Jackman's one-man show, but we get the drift from "Oh what a beautiful moron" and we still love the Chita/Rita West Side Story spat, the Phantom and the Mucus of the Night, and the pastiche Sondheim highlight of "Into the Words," Sweeney leading the sing-along with his cut-throat.

But are we a little less keen on (and less interested in) Idina Menzel "Defying Subtlety," or Mandy Patinkin squabbling with Patti LuPone, or even Ben Lewis doing a perfect Alex Jennings as Willy Wonka ("Come with me, and we'll see, a show with no imagination")?

All faith is restored, though, with the next best spoof after Miss Saigon, a Lion King digest ("A story so bizarre-y, it's Hamlet on safari" - it is!) where the animal cast feel the pain tonight, weighed down with cuddly toy headgear, necks in braces. And have you seen Once? Once is enough! Jersey Boys? "Walk like a man, sing like a girl!"

Nothing is sacred, thank heavens; or is it? The wrong kind of line may be crossed with a finale in which the banners and logos of major sponsors – Disney, BP, Warner Brothers, American Airlines, Exxon, The Times, McDonalds – are lowered during the Nazi anthem ("Tomorrow Belongs to Me") from Cabaret.

That makes decidedly small beer of send-ups of the already sent-up musicals – "Book of Morons" and Spamalot – while Sophie-Louise Dann, a natural comedienne, finds diminishing returns in almost skewering Liza, Julie Andrews and Angela Lansbury. Still, I laughed myself silly for one-and-a-half hours out of two, and that's not too bad a return.