Glassheart (song)

"Glassheart" is a song recorded by British singer-songwriter Leona Lewis for her third studio album of the same name (2012). The song was conceptualised by Lewis and frequent collaborator Ryan Tedder at his family home in Denver, Colorado. As she was experiencing a stressful time in her life, Lewis wanted to create an uptempo dance track with Tedder as she felt a ballad would make her more upset. It was co-written by Lewis and Tedder alongside Brent Kutzle, Noel Zancanella, Justin Franks, Fis Shkreli and Peter Svensson. Production of the song was handled by Tedder and Franks, with the latter credited under his production alias DJ Frank E. It was co-produced by Zancanella, Kutzle and Shkreli.

"Glassheart" is an up-tempo dance song that incorporates elements of dubstep, grime and house music. Lyrically, it is about a woman's fear that her boyfriend will leave her and thus she protects her emotions and her heart from breaking. The song received positive reviews from music critics, many of whom praised the musical direction and its grimy, dubstep breakdown. Upon the release of Glassheart, the song debuted at number 27 on the UK Dance Chart due to strong digital download sales during the first week of Glassheart's release. It debuted at number 167 on the UK Singles Chart. Lewis has performed the song at London nightclub G-A-Y and an acoustic version for UK newspaper The Sun's Biz Sessions.