"321" was written by Chris Crippin, Jacob Hoggard, Tommy Mac, Dave Rosin and Jim Vallance, while production was handled by Brian Howes, who also attributed songwriting for the track.[2] It was written in June 2005 in Vancouver, British Columbia.[3] It was recorded at Armoury Studios, Greenhouse Studios and Hipposonic Studios in Vancouver.[3] The song is about expressing both anger and regret towards a girl following an emotional meltdown.[4] According to songwriter Jim Vallance, he came up with the song title because he thought "321" would "make a great title."[3] The song won the SOCAN No. Song 1 Award in 2007.[3]
Music video
The music video for "321" was released on March 31, 2006, and was directed by Sean Michael Turrell.[5] It reached number one on Canada's MuchMusic Countdown in the week of June 9, 2006.[6] The video was nominated for People's Choice: Favorite Canadian Group at the 2006 MuchMusic Video Awards.[7]