Stephen Schwartz’s untold story of the witches of Oz holds up well after more than a decade entertaining audiences

When Stephen Schwartz's 'untold story' of the witches of Oz opened in London in 2016, I recall being pinned to my seat by the power of Idina 'Let it Go' Menzel's voice.

Back then it seemed a visually bold, brash affair, packing some jarringly under-explored strands into frenetically energetic storytelling.

I might not have predicted it would still be going strong 13 years later, but what do I know?

Revisiting it this week, it's held up remarkably well, the fantasy elements, humorous riffing on the MGM film and Frank L Baum's original, and memorable songs have stood the test of time - from the decibel heavy Defying Gravity which closes the first act to the quietly moving unreqited lovesong, I'm Not That Girl.

I still think that Oz is more of an emotive touchstone for American audiences as born out by the accents around me, but Schwartz has weaved a timely plea for tolerance around Gregory Maguire's source material.

The back stoy of the green-skinned Wicked witch of the West shows how being shunned for being different can corrupt a good nature.

Sent to Madame Morrible's Academy to care for her wheelchair-bound sister NessaRose, Elphaba meets shiny, blonde, smug Gerlinda the Good witch of the North.

They clash over indolent love rival Prince Fiyero, and the scapegoating and caging of Oz's animals, but when Elphaba's power is unleashed when she's angry, there are forces who want to harness it to their own ends,

Wicked plays on the nuances of that very word, so there's no real baddie, although, as in the original, the Wizard's weakness leads to wrongdoing.

And let's just say that Morrible rhymes with horrible.

By the time the never-seen Dorothy whirls into Oz, crushing the Wicked Witch of the East and snatching her sparkly slippers, Elphaba has been forced on the run from Emerald City with her winged monkeys and castigated as evil.

Hearteningly the biggest takeaway is the touching female friendship between Glinda and Elphaba culminating in the gorgeous duet Changed For Good - Schwartz is indeed a master at telling a story through song.

There remain jarring leaps in Winnie Holzman's book but Eugene Lee's steampunk-meets art deco set and Susan Hilferty's sculptural costumes are stunning.

And in the latest pairing Alice Fearn's Elphaba and Sophie Evan's Glinda are note perfect in both voice and performance treading the right line between humour, hubris and emotion.