Songfacts®:

• This soaring ballad is a collaboration between Australian singer-songwriter Sia, Toronto R&B crooner The Weeknd, and Philadelphia producer Diplo, who as well as heading his own dancehall project (Major Lazer) has also provided the soundscape for a succession of pop hits such as Usher's "Climax" and Chris Brown's "Look At Me Now."
• The song started as a track that Diplo sent to Sia. Her reaction was immediate: "For the first time ever, I called someone and said, 'Do not send that track to anyone else - I'll pay for the track tomorrow,'" she recalled to Billboard magazine. "And he said, 'You don't have to pay for the track, you dingaling, it's yours.'"
  
  Sia wrote lyrics for the song about finding love after enduring heartbreak and pain, hoping that Katy Perry would record it, maybe for The Hunger Games: Catching Fire soundtrack. Perry passed, so the Australian songstress did her own vocal. Sia's manager got the Weeknd to add his falsetto to the mix, anticipating it would enhance the song's chances of being chosen for the soundtrack. The plan worked and after Sia was shown an early draft of the movie, she rewrote the lyrics to make the song fit the film franchise.
• The song's music video reunites "Chandelier" director Daniel Askill, choreographer Ryan Heffington and Dance Moms star Maddie Ziegler. The clip features a dance battle between a shirtless Shia LaBeouf (Transformers, Fury) and a blonde-bobbed Maddie Ziegler in a giant bird cage.
  
  The intimacy between the two actors provoked concerns of pedophilia on social media. Sia addressed the outcry on Twitter describing the pairs' performance as "These two warring 'sia' self states."
  
  She added, "I apologize to those who feel triggered by #ElasticHeart My intention was to create some emotional content, not to upset anybody."
• Maddie Ziegler thought Shia LeBeouf did "really well" considering he hadn't had much dance experience before the video shoot. She recalled to MTV News: "I was confused, like, 'Wait, Shia's not a dancer, is he?' And everyone was like, 'No.' But he actually did really well, he did. He wasn't a bad dancer at all. For him, it was mainly fighting, and acting, and running around. And screaming."
• Sia would hide her face during performances of this song (and also "Chandelier"), as she was determined to deter the intrusions on fame and shield herself from the judgment of the Internet. One of her more intriguing performances of the song was on the Ellen show, where she sang it with her head protruding from a white box, her eyes covered with the wig. The visual component was handled by Maddie Ziegler, who did an interpretive dance from the box with several girls in similar boxes behind her.
• Sia brought out Maddie Ziegler to help her perform the song during her appearance on Saturday Night Live. Whilst the Aussie songstress faced stage right, her face covered in a veil from the nose up, Ziegler re-enacted her video dance with Denna Thomsen, who was standing in for Shia LeBoeuf. Sia also sang "Chandelier" on the show alongside a sad-looking mime.