The following year, the Military Wives and Gareth Malone, both involved with the reality television show "The Choir" outsold "X Factor" winners Little Mix and a host of social network campaigns for various novelty acts, and in 2012, a supergroup cover of "He Ain't Heavy, He's My Brother", supporting charities associated with the Hillsborough disaster, took the accolade ahead of "The X Factor"s James Arthur. Following the UK Charts' move to Fridays, the 2015 Christmas number one was revealed on Christmas Day; that year's chart was the first in a decade to not feature the "X Factor" winner's single in the top two. Amazon Music has released a number of exclusive festive tracks since 2018 recorded with acts such as Jess Glynne, Katy Perry, and Justin Bieber, none of which have topped the charts. More recently, non-traditional acts have been successful with novelty songs released for charity, most notably YouTubers LadBaby who achieved number one in 2018, 2019 and 2020 raising money for the Trussell Trust.