By DAILY MAIL REPORTER
Low note: Christina Aguilera looked a mess as she took to the stage to perform at the Michael Forever concert in Cardiff, United Kingdom
Christina Aguilera shocked fans today as she emerged on stage at the Michael Jackson tribute concert in a dishevelled state.
The 30-year-old singer performed at the Millennium Stadium in Cardiff, Wales, today as part of the controversial show.
Her blonde hair, which was filled out with long extensions, was mattered mess and her skimpy corset and fishenets did little to flatter her very curvy figure.
Bad hair day? The singer's blonde mane looked mattered and unkempt
She belted out one of the King of Pop's favourite songs, Smile by Charlie Chaplin, with her usual flair but her outfit certainly hit a low note.
She later changed into a more demure navy dress, with military detailing favoured by Jackson, which was more forgiving on her frame.
What was she thinking? The star's skimpy costume did little to flatter her curvy figure
The lead up to the Michael Forever concert plagued by controversy and largely overshadowed by the Los Angeles manslaughter trial of Jackson's doctor.
It was marred by fan criticism, sluggish ticket sales and dissension within the Jackson family.
Costume change: Christina swapped into a more demure dress which featured military detailing
The Black Eyed Peas pulled out of the lineup this week, citing 'unavoidable circumstances'.
And Jennifer Hudson all cancelled at the 11th hour, and she didn't hide her frustration at the show's organisers.
She tweeted earlier today: 'To my uk fans that were coming to the mj show in wales. I will no longer be attentding due to major production issues.
'I would have thought they would have informed you all by now , so since they did not , I am. Thank u for your support.'
Still, the show went on with a lineup that also included Cee Lo Green, Jamie Foxx, Gladys Knight and Smokey Robinson, and British stars Leona Lewis, Alexandra Burke, JLS and Diversity.
Honouring their father: Prince Michael, Blanket and Paris took to the stage in iconic clothing at the Michael Forever Tribute Concert at the Millennium Stadium in Cardiff
Jackson's three children were also present for the concert.
'We're very happy to be here on this special night to honor our father,' said 13-year-old Paris, who made a brief onstage appearance alongside brothers Prince, 14, and 9-year-old Michael Joseph Jr., known as Blanket.
The children wore outfits evoking their father's famous styles - Paris most strikingly, in a red and black Thriller-style jacket. Blanket stood stoic and shy, but the older children smiled and appeared confident in the spotlight.
On a stage shaped like a giant glove, the musicians performed songs from across Jackson's career - from his childhood with the Jackson 5 through monster solo albums like Thriller and Bad.
Returning to the spotlight: La Toya Jackson honoured her brother
Participants urged fans to ignore the criticism and controversy, and to revel in the celebration of Jackson's musical legacy.
'It's not about the controversy,' said R&B star Ne-Yo, who kicked off the show with a rendition of Billie Jean, complete with some passable moonwalking.
'It's not about the trial. It's not about his death. It's about celebrating his life. It's about celebrating his music.'
The 50,000-strong crowd at Cardiff's Millennium Stadium did just that, roaring with approval as Jackson's brothers Marlon, Tito and Jackie - three-fifths of the original Jackson 5 - took the stage to perform Blame It On the Boogie with British boyband JLS.
American friends: Cee Lo Green and Ne-Yo crossed the Atlantic and descended on Wales to take part
'Can you feel his spirit in the house tonight?' asked Marlon. Judging by the cheers, the fedora hats and the sequined gloves in the audience, many could.
Jackson died in June 2009, at age 50, as he was preparing for a string of comeback concerts in London.
His last hours are being relived in graphic detail at the manslaughter trial of Dr. Conrad Murray, accused of giving Jackson a lethal dose of the anesthetic propofol and other sedatives in the bedroom of his rented mansion on June 25, 2009.
'This is a great counter-act to that,' said Motown great Smokey Robinson, who gave a soulful rendition of 'She's Out of My Life.' 'And it gives people something happy to do, rather than thinking about what's going on in the trial.'
Voice of an angel: Leona Lewis performed at the Michael Forever concert with a host of ballerinas joining her
The show mined a rich trove of Jackson hits. Leona Lewis crooned I'll Be There, Beyonce delivered the early single I Wanna Be Where You Are and Jamie Foxx performed Rock With You.
'Tonight is a history lesson,' Foxx told the crowd. 'We're going to cover five decades of greatness.'
The concert has divided the King of Pop's family and followers. The three brothers, sister La Toya and vocal group 3T - composed of three of Michael's nephews - all performed, while 81-year-old matriarch Katherine was in the audience.
But Michael's brothers Jermaine and Randy and sister Janet have stayed away, saying it is wrong to hold the show at the same time as Murray's trial.
Fix up, look sharp: Jamie Foxx scrubbed up well in a white jacket and black bow tie as he presented the show with radio presenter Fearne Cotton
On fire! Alien Ant Farm set the stage alight with pyrotechnics with a performance to remember in Cardiff
Christina Aguilera "SMILE" Michael Jackson tribute.
Michael Forever Tribute Concert - October 8th 2011