[3][4] The song is dedicated to his great friend and musical collaborator Luke Liang, who died following a battle with mental health.

The song was originally a ballad, but Sebastian changed it into "an upbeat, poignant song about the choir of voices Liang has joined in death, and the choir of voices "keeping his light alive" on earth.

[5] The music video for "Choir" was directed by James Chappell and released on YouTube on 17 June 2019.

[7] The remix video was also released on 27 September 2019 through Alan Walker's YouTube channel.

[8] It was filmed in a church in Newtown, a bus depot in Marrickville and Sea Cliff Bridge, Wollongong.