5 Seconds of Summer

5 Seconds of Summer formed in Sydney in 2011, beginning as a group of school friends at Norwest Christian College who posted cover songs on YouTube. Luke Hemmings started the channel before drawing in Michael Clifford and Calum Hood, with drummer Ashton Irwin joining that December. A major-label deal followed, and the band's profile grew fast after they toured internationally as support on One Direction's Take Me Home Tour.

Their early material leaned on pop-punk templates: fast tempos, palm-muted guitars, choruses built for crowds. They broke through with singles including "She Looks So Perfect" and "Youngblood". The self-titled debut album reached number one in eleven countries in 2014, and its follow-up, Sounds Good Feels Good, topped charts in eight countries the following year.

Youngblood, released in 2018, gave the band a third consecutive number-one album in Australia and made them the first Australian act to place three albums at number one on the US Billboard 200. They were also the first band, rather than vocal group, to see their first three full-length albums all debut at the top of that chart.

Over subsequent albums the band moved toward a broader pop-rock sound, adding synthesisers and funk-inflected basslines while keeping the four-piece guitar-band setup. Luke Hemmings handles most lead vocals, with Clifford, Hood and Irwin all contributing to writing and singing. Their fourth album, Calm, released in 2020, gave them a fourth straight Australian number one.

By 2020 the band had sold more than ten million albums and over two million concert tickets worldwide, with streams of their songs passing seven billion. In 2019 they received the APRA Outstanding International Achievement Award. Live, they work at arena scale, and older pop-punk material still surfaces alongside the later pop songs.