Crystal Castles consists of producer Ethan Kath and vocalist Alice Glass. They are named after the lyrics "The fate of the world is safe in Crystal Castles" and "Crystal Castles, the source of all power" both from the theme song for She-Ra's fortress. Ethan Kath formed the band alone in December 2003, in Toronto, Canada. In April 2005, Glass recorded vocals over five original instrumentals by Kath. The band's first single ("Alice Practice") was actually a microphone test by Glass. She was not aware that the recording existed until London Uk's Merok Records asked to release the track on vinyl.