In Mykonos, the 'Groups' category visited Tulisa Contostavlos with her guest, Jessie J. 

The Keys performed Beyoncé's 'Best Thing I Never Had' to which both popstars agreed that Charlie was the star of the band. 

Girlgroup, Estrella, took on Rihanna and Eminem's 'Love The Way You Lie', while the engaged couple, Girl V Boy, sang Kings Of Leon's 'Use Somebody'.

The Lovettes took on The Saturdays' 'Forever Is Over' and left the judges feeling disappointed, as did The Risk, who were put together by Tulisa, and performed Jordin Sparks' 'No Air'.

The Essex duo, 2 Shoes, made Ke$ha's 'Tik Tok' their own by slowing it down. Nu Vibe brought some humour to their performance of Tinie Tempah's 'Written In The Stars' mixed with 'Nobody's Perfect' by Jessie J, who loved their performance.

Another band that was created by Tulisa, Rhythmix, won over Tulisa and Jessie with Fergie's 'Big Girls Don't Cry'.

Over in Miami, Kelly Rowland and Jennifer Hudson saw eight performances from the 'Girls' category.

16-year-old Amelia Lily sang Katy Perry's 'Alien' and Rowland's response was "Katy who?". Sophie Habibis also blew the judges away with Adele's 'Some Say I'd Be Better Without You'.

New girl Sarah Watson, who replaced Sian Phillips, sang Keri Hilson's 'Knock You Down' and both judges felt that she's not ready for the competition. They also felt that there were a few kinks to be worked on after Jade Richards' performance of Bonnie Raitt's 'I Can't Make You Love Me'.

The girls who got the highest praise were 17-year-old Melanie McCabe who performed Bruno Mars' 'Grenade', Holly Repton (16), who sang The Script's 'For The First Time', Misha Bryan (19), who sang 'Fly' by Nicki Minaj and 16-year-old Janet Devlin, who sang Christina Aguilera's 'Beautiful'.

In Barcelona, Louis Walsh and Sinitta were treated to songs from the 'Overs' category.

Walsh gave Sami Brookes (31) and Joseph Gilligan (26) great compliments with Brooks singing Alicia Keys' 'Streets Of New York' and Gilligan singing Bruno Mars' 'Just The Way You Are'.

45-year-old Johnny Robinson sang 'Love Is A Losing Game' by the late Amy Winehouse and Walsh questioned his versatility. 

Terry Winstanley (41) performed Rod Stewart's 'Handbags and Gladrags' and Carolynne Poole from Huddersfield sang Lady Antebellum's 'Need You Now'.

48-year-old Goldie Cheung had a performance to remember with Jennifer Lopez's 'On The Floor'. Sinitta's response was: "What was that?"

Sinitta noted that 28-year-old soldier, Jonjo Kerr, had a certain sincerity when he performed Adele's 'Don't You Remember'.

However, Walsh said that he loved 26-year-old Kitty Brucknall's performance of 'Beautiful Disaster' by Kelly Clarkson, but her dive into the pool may have ruined it. "I love her intensity but then she talks her way out of it. I'd say she'd be a nightmare to mentor", he said. 

Up in the Los Angeles hills, Gary Barlow and Robbie Williams saw eight performances from the 'Boys' category. Some shone, like 23-year-old Marcus Collins, who sang Embrace's 'One Big Family'. 

Unfortunately, the youngest in the category, 16-year-old Luke Lucas had to be asked to stop and start again with Shontelle's 'Impossible'. Williams said even though he was out of key, he still held "a bit of a candle for him just because of his first audition".

For what John Wilding (19) lacked in impact with his version of Cheryl Cole's 'Promise This', Craig Cotton (22) made up for. His take on Beyoncé's 'Halo' hit Williams in the chest. 

The Take That stars got nostalgic over Frankie Cocozza's hair but Barlow said that with his performance of Rihanna's 'What's My Name', the 18-year-old has gone up a level. 

Williams felt that Joe Cox's song, 'Knocking On Heaven's Door' by Bob Dylan, didn't allow him the 17-year-old to display his range. He also said that Max Vickers' take on Paramore's 'The Only Exception' sounded as if his "mum just told him to turn off his X-Box".

James Michael sang the unusual choice of Bon Iver's 'Skinny Love' but the two singers enjoyed his performance.

Tomorrow on The X Factor, the judges and their helpers will have to send four of their acts home.

Tune in to ITV1 at 7:30pm tomorrow (October 2) to see who gets sent home. 

Check out two of the auditions from tonight's show below: