Whitney Houston, LG Arena, Birmingham

The damaged diva's opening words are prophetic. "To all the haters in the place," she sings, in the opening number of her first night in the UK, "I ain't singing for you ..." Thus begins a show that, within hours, will become a national scandal.

In truth, she doesn't sing those words, she mouths them. As she totters back and forth, a radio mic headset slung around her face, her mastery of the melody is suspiciously precise. A touch of Auto-Tune is going on, at the very least. Then the radio mic is removed by a roadie who hands her a glittery hand-held replacement, which she promptly flings at arm's length in a dramatic gesture ... and the vocals keep coming regardless.

Whitney Houston had an eventful Noughties. It began with lifelong friend Burt Bacharach having to fire her from the 2000 Oscars show after erratic behaviour in rehearsals, which may or may not have been connected to the drug use to which she would later confess, and for which she was in and out of rehab. After the end of her turbulent marriage to Bobby Brown in 2006, she found herself in such financial difficulties that she was ordered by a court to auction many of her possessions including, humiliatingly, items of underwear. In 2009, making a comeback on The X Factor, her malfunctioning bra strap only seemed indicative of wider problems still unsolved.

The Australian leg of the Nothing But Love tour spawned headlines, with angry fans demanding refunds after a performance in Brisbane. On arriving in France, Houston was taken to hospital with an "upper respiratory infection" which forced her to postpone shows in Paris, Manchester and Glasgow. Now the comeback machine grinds on.

So here she is, telling us "I'm feeling pretty good myself, thank you for asking", and repeating variations on the phrase "I love you too", suffixed with a spot of barbed emotional blackmail: "Thank you for your loyalty..." That loyalty is stretched to the limit.

Her voice, seemingly about an octave deeper than the Whitney who sang the hits, is ragged and raw, and she asks for the air conditioning to be turned off, singing an impromptu ad-lib (rhyming "sick" with "quick") about how she's just got over a cold. Between songs, wheezing and panting and occasionally breaking into a scary Wicked Witch of the West cackle, she plays for time, breaking off to sign autographs. Suddenly, telling us she's going to get changed, she introduces her brother, the unshaven but besuited Gary, who croons her early ballad "For the Love of You" no more than adequately. The band strike up "Queen of the Night", the rock'n'soul single from The Bodyguard, but still Whitney is nowhere to be seen, her backing singers doing all the work. This is followed by a CD recording of "One Moment in Time", accompanied by a montage of classic WH moments.

After 15 minutes, there's still no sign of Whitney. How long does it take to change into a spangly black evening dress? By now, there's booing and calls of "Where are you?", until she finally appears, acknowledging, "I heard you got mad, I heard you were a little pissed off." No kidding, Whitters. After a point, whether or not you're a fan of Houston pales against the wider issue of value for money.

Personally, the prospect of a whole Houston concert is a bit like eating an entire box of Terry's All Gold, and the detrimental effect she's had on pop is incalculable, if inadvertent (the idea, propagated by all from Beyoncé and Xtina to Leona and Alexandra, that ululation and melisma is the proper way to sing). We do get one moment of brilliance. "It's Not Right But It's OK", with Rodney Jerkins' extraordinary glockenspiel arrangement, is almost unruinable. The rest of the set is not. "Saving All My Love For You", Whitney's once-beautiful debut single, is tossed away as part of a stool-perched medley, and turned into an all-but-unrecognisable display of vocal gymnastics. Heckles of "Sing the song properly!" meet petulant refusal: "It's my show, I'll sing it the way I wanna sing it..."

Houston lurches awkwardly from one horror to the next. The Bible-bashing gospel screamer "I Love the Lord" is greeted by stony faces from secular Brits. Her attempt at the Eighties disco smash, "I Wanna Dance With Somebody", is on only vague terms with the actual melody, and "How Will I Know" is little better. This after she's had the nerve to tell us: "If you're gonna sing along, be in the right key. I've seen X Factor."

During "My Love", presumably to reflect such lyrics as "If we wake up to World War Three", we're shown images of carnage from Afghanistan and Iraq, and abject survivors of Hurricane Katrina. At one point, we see the word "HELP!" painted in big white letters on a wall. I couldn't have put it better.

The concert climaxes, inevitably, with "I Will Always Love You". Houston's mirror-shattering version always lacked the humility and poignancy of Dolly Parton singing it to Burt Reynolds in that little Texan whorehouse, but tonight she murders it. The gap before the big note – you know the one – is milked for minutes, and when she finally steps forward to belt it out, she misses by half a mile.

She'll return for an encore "Million Dollar Bill" and "I'm Every Woman", but by then most people are already streaming down the aisles, wondering why they paid between £55 and £108 for their tickets.

It's a show which, if not quite the human car crash that's been reported elsewhere, should never have happened. Cold or no cold, Whitney is clearly unready for all this, and the promoters – Marshall Arts by arrangement with WME2 – must take a long look at themselves.

It's not right, and it's certainly not OK.

Next Week:

Simon pops in the earplugs to brave Lou Reed's infamous Metal Machine Music live