Glassheart (song)

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.

Lewis has performed the song at London nightclub G-A-Y and an acoustic version for UK newspaper The Sun's Biz Sessions.

[1] The aim of the trip was to visit Tedder and his family, as well as conceive ideas and themes for material to be included on Glassheart.

[1] Lewis stated that she did not want to sing a ballad which would make her "more sad", therefore they decided to work on an upbeat dance song instead.

[4] "Glassheart" was co-written by Lewis with Tedder, Brent Kutzle, Noel Zancanella, Justin Franks, Fis Shkreli and Peter Svensson.

[4] Instrumentation of the song was provided for by multiple musicians: Shkreli was appointed head of sound design, and was also a drum programmer along with Freesh and Trent Mazour.

"[5] The chorus is built on a "transcendent house beat" as Lewis delicately sings the lines "Promise that we'll never fall apart/ And I'll love you with my Glassheart".

[5] Jenna Hally Rubenstein for MTV Buzzworthy was complimentary of the song, writing that Lewis had "[upped] the musical ante big time".

[5] Rubenstein continued to highly praise the inclusion of the dubstep transition due to the fact that she thought she would never "use the words 'dubstep' and 'Leona Lewis' in the same sentence.