Girls Aloud by Louis Walsh until 2005 when Hilary Shaw replaced him. The new group competed with the boys' winning group, One True Voice to have 2002's Christmas number one single. Girls Aloud won the battle with their single "Sound of the Underground", produced by Brian Higgins and Xenomania. The song spent four consecutive weeks at number one and was certified platinum in March 2003. The song received critical acclaim; Alexis Petridis of "The Guardian" stated that "it proved a first: it was a reality pop record that didn't make you want to do physical harm to everyone involved in its manufacture".
Chemistry (Girls Aloud album) on 2 December 2005 and in the United Kingdom on the following Monday. In addition to the standard edition of the album, a limited edition with a bonus disc was also released. The bonus disc contains Christmas music, including covers and original songs produced by Xenomania under the moniker Festiv Gifts. The songwriters also took on Christmas-related pseudonyms. In Australia and New Zealand, the album was released on 20 February 2006; however, it failed to generate much interest. Additionally, "Chemistry" and other Girls Aloud releases appeared on the US iTunes Store on 26 June 2007. The album's first single was