Musically, the sound of "Meltdown" has been described as hard rock, with influence from metal, drawing comparison to the Smashing Pumpkins. The guitarwork throughout the album recalled the likes of Black Sabbath and Metallica, and featured numerous solos from guitarist Charlotte Hatherley. It saw a shift away from the pop punk style of "Free All Angels", resulting in the band's heaviest-sounding release. Discussing the album's title, Wheeler explained: "Why? Cos it’s a meltdown. A full-on rock monster. A real face-melter. It’ll tear your face off." Wheeler wrote all of the songs, except for "Meltdown" (which he co-wrote with Hatherley), and "Out of the Blue" (which he co-wrote with bassist Mark Hamilton). Dracula is a reoccurring lyrical theme throughout the album.