This regretful track was co-written by Good Charlotte's Benji and Joel Madden along with Louis and Michael Biancaniello and Louis' frequent songwriting partner, Sam Watters. It finds the guys unable to escape the memories of a failed relationship. The song was released alongside the pre-order of the 5 Seconds of Summer album on iTunes on June 23, 2014.
5 Seconds of Summer filmed a music video for the song in San Pedro and Los Angeles in late April 2014.
Benji Madden told The Official Charts website: "5 Seconds of Summer remind me of Good Charlotte in the best possible way. They're a younger us. I'm glad they're doing this sound and I'm very happy to pass the torch."
Meghan Trainor and her producer Kevin Kadish originally wrote "All About That Bass" for another artist to record. However, after Epic Records boss LA Reid heard Meghan play a demo of the song on a ukulele, he signed the young songwriter to his label and told her she should sing it.
"Lean On" was originally sent by Major Lazer to both Rihanna and Nicki Minaj's camps as a slower reggae track. After both parties rejected the tune, Major Lazer recruited Danish singer MØ to supply vocals and recorded it themselves.