Award-winning musician Christopher Cerf has composed music for the famous children's television show Sesame Street for 40 years. During this time, he has written more than 200 songs intended to help children learn how to read and write.
But these innocent children's songs were abused for inhumane purposes.
"It is music's capacity to take over your mind and invade your inner experience that makes it so terrifying as a potential weapon."
- Thomas Keenan, the director of the Human Right's Project at Bard College
In 2003, it transpired that US intelligence services had tortured detainees at Guantanamo Bay and Abu Ghraib with music from Sesame Street.
Human rights researcher Thomas Keenan explains: "Prisoners were forced to put on headphones. They were attached to chairs, headphones were attached to their heads, and they were left alone just with the music for very long periods of time. Sometimes hours, even days on end, listening to repeated loud music."
"The music was so loud," says Moazzam Begg, a former detainee at Guantanamo Bay and Bagram. "And it was probably some of the worst torture that they faced."
Stunned by this abuse of his work, Cerf was motivated to find out more about how it could happen.
"In Guantanamo they actually used music to break prisoners. So the idea that my music had a role in that is kind of outrageous," he says. "This is fascinating to me both because of the horror of music being perverted to serve evil purposes if you like, but I'm also interested in how that's done. What is it about music that would make it work for that purpose?"
Cerf embarks on a journey to learn just what it is that makes music such a powerful stimulant. In the process, he speaks to soldiers, psychologists and prisoners tortured with his music at Guantanamo Bay and finds out how the military has been employing music as a potent weapon for hundreds of years.
The resulting film, Songs of War, explores the relationship between music and violence.