164 Songs Were Banned After 9/11
It is impossible to overestimate the seriousness of the September 11 attacks in light of what transpired on that day, the lives lost, and the lasting effects they had on not only America but also the rest of the globe. Since then, nothing has truly been the same. After that, there was understandable anxiety and terror, and occasionally those feelings showed up in odd ways. The prohibition of songs was one of them.
The general consensus was that anything that would serve as a reminder of what happened should not be played, but the full list included 164 songs, some of which were more difficult to understand than others. These were communicated to the on-air employees by the leaders of the majority, if not all, of the major American stations. The songs weren't necessary outright, unambiguously forbidden, but it was encouraged not to play them.
On paper at least, several songs made sense right immediately, for example, Metallica's Seek and Destroy and Drowning Pool's Bodies. There were many metal and rock songs that invoked images of destruction and death. The list included each and every song by Rage Against the Machine.
Other options appeared to be a little more obscure. Louis Armstrong's song What a Wonderful World. The Clash's Rock the Casbah. You may argue that those were inappropriate choices; perhaps Rock the Casbah sounded too Middle Eastern at the period when anti-Muslim sentiment was rampant? But that's a bizarre and a reach.