Ethan Kath met Alice Glass in Toronto and asked her to record vocals over tracks he had been working on since 2003. This resulted in the track “Alice Practice”, which was initially shelved for six months but garnered much attention when finally posted online. The pair then decided to formally become a group, picking out stage names together, with the name ‘Crystal Castles’ pulled from a line in the cartoon She-Ra: Princess of Power: “The fate of the world is safe in Crystal Castles.” Alice Practice became the band’s first limited vinyl release in 2006.
Several limited edition 7″ vinyl singles followed in 2006 and 2007 on various independent labels, including two on London’s Trouble Records. In February 2008, Kath said his aim was to “…make the most annoying sounds ever scream over and then we’ll try to open for Melt Banana”. Later in the year Lies Records collected most of the vinyl singles and released them on CD and 12″ vinyl for the first time, along with many previously unreleased tracks and 3 songs recorded just for the collection which made their debut album. This eponymous debut album was included in NME’s “Top 100 Greatest Albums of the Decade” list at number 39. The record included tracks like “XXZXCUZX ME”, which Kath states he made ‘grating’ on purpose. When questioned about his motives behind this, Kath responded with “To weed out the wimps, to annoy the posers. We are saying, ‘We are not for you'”.