This is a list of songs purportedly deemed inappropriate by Clear Channel Communications following the September 11, 2001 attacks. In the days following the attacks, many television and radio stations altered normal programming in response to the events. During this period, the rumor spread that Clear Channel and its subsidiaries had established a list of "songs with questionable lyrics" that stations might not want to play after the attacks. This list was distributed by the independent newsletter Hits Daily Double, which is not affiliated with Clear Channel.
Snopes did research on the subject and concluded that the list did exist as a suggestion for radio stations but noted that it was not an outright ban on the songs in question
Wikipedia
via. Beatking