U2 is credited with composing the music for all of "Achtung Baby"s tracks, despite periods of separated songwriting. They wrote the music primarily through jam sessions, a common practice for them. The album represents a deviation from the sound of their past work; the songs are less anthemic in nature, and their musical style demonstrates a more European aesthetic, introducing influences from alternative rock, industrial music, and electronic dance music. The band referred to the album's musical departure as "the sound of four men chopping down The Joshua Tree". Accordingly, the distorted introduction to the opening track "Zoo Station" was intended to make listeners think the record was broken or was mistakenly not the new U2 album. Author Susan Fast said that with the group's use of technology in the song's opening, "there can be no mistake that U2 has embraced sound resources new to them".