Foreground Vs Background: The Foreground of the song are clearly the repetitive, simple vocals. They stay largely the same throughout the song. The Background, on the other hand, is constantly evolving. Percussion instruments, Synth Lines, background vocal lines, and a dozen other flourishes constantly come and go. As such, by about halfway through the song, the lines between Foreground and Background get blurred, since the listener is completely accustomed to the vocals that do still completely dominate the recording, but is kept interested by the constantly changing Background.