Deicide's Fuck Your God was used in American prisons in Iraq. Metallica's Enter Sandman was and still is used in Gitmo as far as I know. AC/DC and Barney have been used as well. Psyops doesn't leave scars so it's not torture, naturally.

Multiple Sources: http://lmgtfy.com/?q=music+played+at+gitmo

Don't remember. I know it wasn't Michael Bolton because he is banned by the Geneva convention