5 Seconds of Summer, often shortened to 5SOS, are an Australian pop rock band from Sydney, New South Wales, formed in 2011. The group consists of lead vocalist Luke Hemmings, lead guitarist Michael Clifford, bassist Calum Hood, and drummer Ashton Irwin. They were originally YouTube celebrities, posting videos of themselves covering songs from various artists during 2011 and early 2012. They rose to international fame while touring with English-Irish band One Direction on their Take Me Home Tour. They have since released three studio albums and headlined three world tours.