Songfacts®:

• This is the sixth single by the Swedish House Mafia. They are joined on the track by their fellow Swede, John Martin, who also contributed vocals to the trio's "Save The World" hit tune.
• "Worry" had its live premiere at the Swedish House Mafia's July 14, 2012 Milton Keynes Bowl concert and debuted on the radio on Pete Tong's Radio One show on the August 10, 2012.
• The song was inspired by Swedish House Mafia's admiration towards Sydney, Australia. "We were at this amazing house in Sydney by the water," recalled Axwell to MTV News, "and we were trying to take in all the amazingness of Sydney. So we took out a couch and sat in the garden with the ocean view there. And we were like, 'OK, let's make something that sounds how this looks.' "
• The song's music video chronicles Swedish House Mafia's Milton Keynes gig, which was the trio's final ever live show in the UK.
• The song was the trio's sixth and final single before they put their partnership on indefinite hiatus.
• This topped the singles charts in several countries, including Australia, the United Kingdom and the trio's native Sweden. It was also the first song by a Swedish act to break into the Top 10 of the US Billboard Hot 100 since 1997 when Robyn's "Show Me Love" peaked at #7.
• The song returned to the UK Top 40 the following year, following a performance during the X Factor auditions by boy band hopefuls Kingsland.
• John Martin recalled how on arrival in the USA in February 2012 he simultaneously got a text from his manager saying the song was in the Top 10 on the Billboard Chart and turned on the radio in his hire car to find this was the first tune he heard. "Everything changed what seemed like overnight," he said. "When traveling around we heard it constantly on repeat for the whole month. We had never performed the track live at that stage but shortly after I found myself playing in front of 100,000 in Stockholm over a three day period. That was a highlight."
• John Martin told The Sun: "That song was actually written by me and Michel Zitron, my friend that I write with. We sat down in Michel's studio on a Sunday, we were kind of hangover."
  
  "We had this discussion about our relationship with our dads," he continued. "We started to play around with a loop, then this melody came out quickly and we did it in one day."
  
  Martin added: "You have to touch the crying nerve in music. When you mix sad melodies with euphoric tracks. There is something that happens that really works."