The X Factor is a British television music competition to find new singing talent. The eighth series commenced airing on ITV on 20 August 2011 and ended on 11 December 2011. The winner was Little Mix, a four-piece girl group known earlier in the series as Rhythmix, consisting of members Jesy Nelson, Perrie Edwards, Leigh-Anne Pinnock, and Jade Thirlwall. They became the first act in the groups category to win in the show's history with new judge Tulisa Contostavlos emerging as their winning mentor. Also they are the only girl group to get to the final. Louis Walsh was the only judge from series 7 to return, while Gary Barlow, Kelly Rowland and Tulisa Contostavlos joined the panel as replacements for former judges, Simon Cowell, Dannii Minogue and Cheryl Cole. During week 4 of the live shows, series 5 winner Alexandra Burke replaced Rowland due to a throat infection. Dermot O'Leary presented the show on ITV, while Caroline Flack and series 6 runner-up Olly Murs co-presented the spin-off show The Xtra Factor on ITV2, replacing Konnie Huq from the previous year.