The only single issued from the album, it is the only track featuring lead vocals by David Gilmour, with Roger Waters singing the refrains and interludes. The song reached No. 7 on the mainstream-rock chart in the U.S. and went to No. 3 in the U.K.
Written by Waters, "Not Now John" deals with war and criticism of British Prime Minister Margaret Thatcher, as well as general criticisms of the greed and corruption that Waters saw as dangers to society.
The special promotional edition of the "Not Now John" single features a rare white CBS label.
The band was on the verge of splitting up by this point, since the LP is basically a Waters solo record. Founding keyboardist Richard Wright had been ousted during the album's difficult sessions and replaced by Michael Kamen and Andy Bown.
Here's the cover art for the Japanese edition: