Rough Copy, Kingsland, Code 4, Brick City, Xyra and newly-formed girl band Stop Look Listen will join Barlow and guest mentor Olly Murs in New York for the next stage of the competition.
Rough Copy, who originally started as a trio, now comprise Steling, 28, and Joe, 27. The pair sealed their place in New York with a bootcamp performance of 'Stop Crying Your Heart Out' by Oasis.
East London-based five-piece Kingsland have made some sacrifices to get this far in the competition, with three of the group losing jobs because of gruelling practice sessions. Connor, 19, Matt, 25, Jay, 19, Josh, 20, and Thompson, 22, gained praise for their arena performance of Bruno Mars's 'Treasure You' - Louis Walsh even compared the performance to seeing Take That for the first time.
Code 4 impressed the judges with a performance of 'Wake Me Up' by Avicii at bootcamp. The group - 17-year-old Jorden, Ryan, 21, and Jermaine, 25 - formed two years ago as a four-piece, but lost a member recently. In addition to vocals, the trio push themselves with well-rehearsed dance routines.
The only mixed-gender group through to the judges' houses, Brick City, are Yasmin, 23, James, 25, Anton, 27, and Duane, 28. A relatively new band, having only formed in 2013, they still attracted praise with their take on 'Like a Prayer' by Madonna.
Stop Look Listen are a brand-new group, having been put together during the X Factor audition process. Jeanette, 21, and Rielle, 16, auditioned in the girls category, while 22-year-old SeSe first appeared in front of the judges as part of Dynamix. They were chosen after only ten hours of rehearsal together at Boot C amp, impressing with Rihanna's 'We Found Love'.
Xyra, a five-piece girl band, round out the final six, having formed seven months ago after working together in promotions. Beth, 23, Amy, 24, Laura, 23, Sasha, 22, and Nadina, 25, won their tickets to New York by singing 'Billie Jean' by Michael Jackson.
X Factor continues on Saturday, October 5 at 8.20pm on ITV1.