''When we were making our third record, the War LP, we were being thrown out of the studio by the studio manager because we had overrun or something and we had one more song to do. We wrote this song in about ten minutes, we recorded it in about ten minutes, we mixed it in about ten minutes and we played it, then, for another ten minutes and that's nothing to do with why it's called '40'.''
did you know
'40' from the War album almost was never recorded. The band (minus Adam Clayton who had left the studio) had gone over their booked studio time, but convinced the studio manager to let them record '40'. It has closed many show since. The Edge plays both electric and bass guitar on the song.