At the Idaho Correctional Institution, inmates' aural link to the outside world is called the Music Warden. For between one and two dollars a song, the black box will load music into a specially designed prison MP3 player, a small luxury that has replaced FM radios, tapes, or CDs from the prison store. Spin looks at just why two companies have decided that selling songs to prisoners could be big business, why cheap MP3 players could be making prisons safer, and what easier access to music means to the inmates themselves. "It gives me a different coping mechanism, just being able to be here with everyone else, but also not be here," says one inmate serving time for robbery. "Because it's my own music, it brings back memories of stuff that I like and gives me a little normalcy."