but stardom.' Before the voting was announced, the American contestants were shown how the Brits do it - with Cher Lloyd from the UK's X Factor performing her new single Oath live. How the Brits do it: Cher Lloyd was flown in to guest star on the show and wowed the crowd with her new hit Former contestant: The 19-year-old was one of the finalists in British X Factor in 2010 and sang her new single Oath on Thursday's show Wearing a dress to look like cut-down denims and a waistcoat and with knee-high black socks, Cher was joined by Becky G - in black leggings and a gold  top - as well as a team of backing dancers for the high-energy performance. They got a standing ovation from the judges - with host Khloe Kardashian-Odom, in a figure-hugging black dress, calling it "phenomenal". The show also featured a touching performance by another group of special guests - a choir from a struggling inner city performing school that the show helped completely re-equip for their music program. Impressive: Loyd received a standing ovation and host Khloe Kardashian called her performance phenomenal Dressed all in white, the youngsters from Bancroft Middle School in L.A. sang the moving chorus to Coldplay's Fix You after the finalists sang their own parts. The contestants had invited the youngsters to perform as they appeared at a school assembly to surprise them with the new music and recording equipment provided along with Best Buy. Next week