[2] On reading the script, Beltrami said that Joon-ho was open to creative ideas,[3] and added that the story was an allegory, and told it in a surreal way, the music had three functions: "It had to the momentum of the characters moving forward on the train; it had to have the personal, emotional aspect of their struggle; and it had to represent this outside world that wasn't a part of what they were and what they longed for [the rich passengers at the front of the train].

"[1][4] While describing the setting as futuristic and also backwards, as "there are people in the train with not much technology", Beltrami used the old-fashioned musical instrument, such as cimbalom, a hammered dulcimer, which had an "antique quality".

He used the text lines from the script, and the storyboards to follow the timing, and created a musical tone played by Beltrami on a mouth organ and vocals performed by his kids, which eventually became the "Wilford Song".

[3] Snowpiercer: Original Motion Picture Soundtrack was published by CJ E&M Music, which released first in South Korea on 21 August 2013.

[8] Four of the instrumental compositions from the soundtrack was performed by Beltrami at the 007 Fimucité at Tenerife International Film Music Festival in the Canary Islands, held during 5–14 July 2013.

[10] The soundtrack release coincided with the Los Angeles Film Festival premiere, where Beltrami conducted a five-minute live performance of the score.

[12] All music is composed by Marco BeltramiWriting for Synchrotones, Pete Simons stated "There are a number of excellent cues here, particularly those featuring his perpetual motion theme.

But then... the orchestra starts to play a more prominent role, the themes become more pronounced and the whole atmosphere becomes more epic – culminating in the truly magnificent "This Is The Beginning".

"[13] James Southall of Movie Wave wrote "the score blends fierce action cues with very rugged suspense and drama – very effectively".