One of the most difficult times for countries and individuals to go through is war. History has shown us that music was used as a way to help soldiers cope and deal with the traumas, stress and issues brought on by war. But music during wars had other uses too.

Music has been used to aid with sieges during wars, persuade people to vote in certain ways, to taunt opponents, to disperse crowds and, in many cases, to torture prisoners of war. The diversity of musical styles and artists employed in such a manner is remarkable. Hugely popular metal bands like Metallica, children's television themes such as Sesame Street, blasts of static noise, chart hits from the likes of Britney Spears and Nancy Sinatra, hip-hop from Eminem... All have been used to pummel people into behaving a certain way. As you can probably imagine, many musicians have been less than thrilled to know that their output is being militarised. Here are nine of the most extreme instances in which music has been used to persuade, destroy or enforce.

_{Music is my weapon (YouTube)}

Probably the most famous examples of musical weaponry being employed occurred during the American occupation of both Iraq and Afghanistan throughout the 2000s. “When laying siege to various Iraqi and Afghani encampments, the US army would endlessly loop certain songs at ridiculously high volumes. The tracks would play day and night, blasting out of huge speakers, until those under siege eventually caved in and surrendered,” notes What Culture.

This is referenced in Apocalypse Now, when the helicopters blast Wagner's Ride of the Valkyries into the Vietnamese landscape. Unsurprisingly, many of the most frequently played tracks on the playlists are by metal bands. The heaviness, distortion and aggression are unbearable for the average listener at the best of times, let alone for a non-western culture exposed them 24/7 at extreme volumes.

_{Music is our weapon (DeviantArt)}

Reportedly, death metal band Deicide's F*ck Your God is used most often, but tracks by Metallica (Enter Sandman), AC/DC (You Shook Me All Night Long), Black Sabbath (Paranoid), Drowning Pool (Bodies), Alice Cooper (No More Mister Nice Guy) and a vast quantity of death and black metal acts can also be located on the playlists. Metallica's James Hetfield has been particularly vocal in his support for the use of the band's music in war zones.

Bizarrely, however, it's not just metal bands that are used. Apparently, the theme songs from the children's television series Sesame Street and Barney & Friends are used all of the time too. Their repetitive nature and simplistic tunes cause severe irritation and mental torture. Jon Ronson, author of The Men Who Stare at Goats, writes that he has seen people subjected to the Barney & Friends theme "screaming so hard it looks as if laughing".

_DeviantArt

Humans react with particular revulsion to musical signals that are not of their choice or to their liking. Many neuroscientific theories about how music acts on the brain—such as Steven Pinker’s notion that music is “auditory cheesecake”, a biologically useless pleasure—ignore how personal tastes affect our processing of musical information. A genre that enrages one person may have a placebo effect on another. A 2006 study by the psychologist Laura Mitchell, testing how music-therapy sessions can alleviate pain, found that a suffering person was better served by his or her “preferred music” than by a piece that was assumed to have innately calming qualities. In other words, music therapy for a heavy-metal fan should involve heavy metal, not Enya.