• "Sound of the Underground" was one of 60 songs that Brian Higgins and Miranda Cooper wrote with the aim of launching their own girl-group. Polydor said they didn't have the right band to perform the song - until, a few weeks later, the idea of Popstars: The Rivals came along.
  

• "No Good Advice" was written by Higgins and Cooper when they were known as Moonbaby and were signed to London Records in the late 1990s. The song chorus began rather differently, with the phrase "I don't like fried rice" (!).

• Higgins says that despite his confidence in the song "Life Got Cold" he wasn't prepared to take the idea of a Girls Aloud version seriously until the band had sung their own version, because a track working "has always got to be based on an artist's performance, not the music itself. But they sang it, and they really nailed the melancholic aspect of it, and it sounded beautiful".

• Love Actually director Richard Curtis phoned Xenomania when they were in a taxi in Berlin, and explained that he thought "Jump" would be a good Girls Aloud single. The aggressive synth sound in the chorus comes from a Jupiter-6 - the idea was that "JUMP!" had to be followed by a sound demanding you to jump.

• The synth rhythm for "The Show" was composed by a Xenomania musician called Jon Shave. The lyrics were intended as a sort of anti-promiscuity message.

• Some of the "Love Machine" lyrics came about through a process Xenomania employ, which is to sing "nonsense lyrics" over a backing track - eventually the nonsense lyrics evolve into more meaningful songwords. The backing track, semi-inspired by The Smiths, is the work of Xenomania musicians Nick Coler and Tim Powell.

• The first version of "I'll Stand By You" was a weird, modernist breakbeat version which sounded like '90s dance act Future Sound of London.

• "Long Hot Summer" was written by Xenomania when the team were in LA. Xenomania visited the Disney offices and were asked to write a song that would feature in the Lindsay Lohan Herbie movie. For various reasons, the track never made the movie.

• The mention of "wicked games" in the introduction of "Biology" is a reference to Girls Aloud almost releasing a cover of Chris Isaak's "Wicked Game" as a single.

• To cheer themselves up, Xenomania went off for a songwriting session in Paris and, while they were there, they sketched out the song that would become "Call The Shots". It was almost put forward as one of the singles to promote the greatest hits album, but was held back as it was considered too downbeat.
  Peter Robinson describes "Call The Shots" as "the greatest pop song of the 21st Century".

• Brian Higgins says that "Can't Speak French" is perhaps the easiest Girls Aloud single they made. The b-side, "Hoxton Heroes", came about when members of Girls Aloud were talking about music with Xenomania - before you know it, a song was being crafted.

• One day, two young Australian musicians at Xenomania, Jason Resch and Kieran Jones, played a '60s-sounding backing track to Brian Higgins and "The Promise" was born. Higgins and Cooper didn't write anything to the backing track for a few weeks - they waited until the right time so they didn't ruin the moment. They eventually wrote the song in seven minutes.

• The emotional twangy guitar noise in "Untouchable" was the result of Xenomania musician Jason Resch responding to a request for something "special". Brian Higgins says he could happily listen to the guitar part for an hour on a loop.

Labels: Girls Aloud, Girls Aloud Singles Boxset