The Thorn features four of the band's tracks recorded with orchestral instrumentation: "Overground" originally appeared on the Banshees' debut album The Scream; "Placebo Effect" was a song from their second album Join Hands, while "Voices" and "Red Over White" were previously released as B-sides from the singles "Hong Kong Garden" and "Israel", respectively.
The Thorn album includes four songs from the band's earlier work, which were originally released in different formats and contexts.