+44

Formed during blink-182's hiatus in 2005, +44 reunited former members Travis Barker and Mark Hoppus while Tom DeLonge pursued Angels and Airwaves. Initially leaning towards electronic sounds, +44 transitioned to alternative rock, taking their name from the UK dialing code. Vocalist Carol Heller briefly joined the band before being replaced by guitarists Shane Gallagher and Craig Fairbaugh. Their debut album, When Your Heart Stops Beating, released in November 2006, featured the hit title track and led to a nationwide tour, despite Barker breaking his arm during filming.

The duo +44, comprising Barker and Hoppus from blink-182, emerged during the band's hiatus in 2005, while DeLonge formed Angels and Airwaves. Shifting from electronic to alternative rock, +44's name references the UK dialing code and saw lineup changes before releasing their debut album in November 2006. Supported by the single "When Your Heart Stops Beating," the band embarked on a nationwide tour despite Barker's arm injury during video filming.