So much of television is bland and formulaic that genuine jaw-dropping moments are few and far between.

But on Sunday evening I caught my reflection on the TV screen and realised I was open-mouthed.

I was on a Yellow Brick Road to TV hell, or possibly heaven. Hard to decide which. I once described watching Lark Rise To Candleford as like being force-fed treacle. But BBC1’s twee period drama looks like Shameless in comparison with its latest offering – Over The Rainbow.

The televised search for a Dorothy for Andrew Lloyd Webber’s West End production of The Wizard Of Oz is, as you’d expect, camp as Christmas.

A giant pair of sparkly ruby slippers dominates the set and a gaggle of stage school starlets in gingham frocks, all dying to be Dorothy, practically elbow each other out of the way during a succession of desperate ‘mash-ups’. Presiding over it all is Lord Lloyd Webber, sitting on a throne, for reasons beyond me.

The show is stretched over Saturday and Sunday evenings, but if you can’t stomach both programmes, I urge you to watch the Sunday results show. It has to be seen to be believed. It largely follows the formulaic TV talent show mix of schmaltz and cruelty, with a wannabe Dorothy booted off by the Lord each week following a sing-off with a rival contestant. “It’s the song they’ve been rehearsing all week, but neither wanted to sing,” smirks host Graham Norton, who adopts a subtle tongue-in-cheek tone and appears to be the only one not taking it too seriously.

The two ‘Dorothys’ with the lowest viewer votes must sing for survival but, before they begin, there’s a pinch of salt rubbed in the wounds when they’re told which one is least popular with the public. Even I think that’s a bit harsh.

Sunday’s lowest votes went to a 16-year-old girl whose bottom lip was wobbling before she started singing. Given the thumbs-down, she was subjected to a frankly sinister send-off song from the other Dorothys, which included the toe-curling line “you ditched her so completely”, sung to the Lord.

Next came a bizarre ritual involving the poor girl taking off her sparkly slippers, which were presented to the Lord. This was when my jaw hit the floor.

Then, waved off by her tearful rivals, she sang Over The Rainbow, perched on a glittering half moon, hilariously hoisted up to the rafters.

Naturally, I’m hooked. Can’t wait for the final; I’m predicting the winner clicking her ruby slippers and heading off on the Yellow Brick Road, trampling over a pile of tear-soaked wannabes. Priceless.