The musical elements of Worlds on Fire by The Butterfly Effect are complex and varied. The song is through-composed, and loosely follows an AABA structure. However, at the refrain, the song changes markedly. The refrain itself is 2 minutes and 40 seconds long, and encompasses a vocal part that is similar to the chorus, but not the same. After the refrain, there are two more verses, although they are harmonically and rhythmically unalike to the first four. The last verse is highlighted by another change in melody, and the song ends in a coda.
Harmonically and rhythmically, Worlds on Fire builds on itself over its progression. The song begins with a plucky bass-line, which rises in pitch for 8 bars, and then repeats. The drum line is not introduced until 0:29. At 1:25, the chorus is introduced with a change in the harmony of the guitar, but at 1.58 the song reverts for the third verse with the addition of an electric guitar that sort of plays in a call-and-response manner to Clint Boge.
At 2.58 the song changes to the refrain, and the introduction of a textural wedge, in which a trumpet and keys begins. At 3.18, the rhythm noticeably changes to much faster. The prominence of these voices with ebb and flow until 5.53, which signals the beginning of the coda. The guitars and drums become much harder, as does the singer’s voice, reminiscent of The Butterfly Effect’s earlier works.
The texture and sound-painting is densest in the refrain, with the addition of the piano, trumpet and strings, and a lead guitar line to the bass guitar, drums and rhythmic guitar. Synthesised layers of Clint Boge’s own voice are also heard.