The live finals of The X Factor 2009 have kicked off – with some memorable performances and more than a few arguments between the judges.

This week the 12 acts were faced with the theme of musical heroes, with more than a few of them opting for songs by this week’s mentor, Robbie Williams. Robbie will perform his new single Bodies on the results show on Sunday.

And kicking things off was Rachel Adedeji, the first of the girls in Dannii’s category, with a lively rendition of Robbie’s Let Me Entertain You. The judges were impressed with Simon telling the teenager she gave a “good performance” although Louis was more enthusiastic. “Rachel you rocked,” he said. “Congratulations.”

Girl group Kandy Rain were next on stage, singing Addicted To Love, and they divided the panel. While Louis and Simon both liked the quartet’s performance, Dannii and Cheryl were unimpressed by their skimpy outfits.

Essex boy Olly Murs fared better with his performance of Robbie Williams’ She’s The One, with his mentor Simon telling him “You remind me of Robbie,” although he was less impressed by Rikki Loney’s jazzy rendition of Amy Winehouse‘s Back To Black.

“It was wet,” he told the Scottish hopeful, “it had no star quality.”

The next trio of acts however, impressed the judges – firstly Stacey Solomon, who was praised for an offbeat song choice, namely the Coldplay hit The Scientist. Miss Frank’s performance of Who’s Loving You also won them plaudits. “I have no qualms in saying you’re my favourite group,” Cheryl told them.

And Jamie Archer delivered a powerhouse performance of the T-Rex classic Get It On, which Simon said was “in a different league from everything else we’ve seen tonight”.

Lloyd Daniels, the youngest of the boys, was described as “a born pop star” by Louis following his performance of Justin Timberlake‘s Cry Me A River, and there was also high praise for Welsh teenager Lucie Jones.

Next on stage were controversial duo John and Edward, who divided the judges with their version of Robbie’s Rock DJ. While their mentor Louis loved their performance, Simon described it as a “musical nightmare”.

The final two performances of the night came from teenager Joe McElderry, who wowed the panel with his rendition of Robbie’s No Regrets, and Danyl Johnson, who sang the powerhouse ballad And I’m Telling You I’m Not Going – a song traditionally sung by a woman.

Although Louis, Cheryl and Dannii all voiced concerns about the 27-year-old’s over-confidence, Simon stuck by his act. “I think I’ve just heard one of the best performance I’ve ever heard in my life,” he said.

The result will be announced on Sunday night’s show, with one act eliminated from the competition.