"40" - Live

This was the last song written for the album. They had already used an extra week of studio time and needed one more song in a hurry, so Bono opened a bible, read from Psalm 40 of Psalms of David, and they put it to music.

The last song on War, it invokes the first track, "Sunday Bloody Sunday," with the refrain "How long must we sing this song."

At a concert in Chicago on April 29, 1987, Bono said: "This is a song that when we were being thrown out of the studio... we spent ten minutes writing this next song, ten minutes recording it, ten minutes mixing it, ten minutes playing it back, and that's nothing to do with why it's called '40.'"