The Disintegration Loops

"The Disintegration Loops is a series of four albums by American avant-garde composer William Basinski released in 2002 and 2003. All albums are recorded in the same form of a tape loop which slowly deteriorates as it passes by the tape head, creating all the more noises and cracks in the music as the theme progresses. The recording coincided with the 9/11 attacks and the album covers and accompanying videos feature a still skyline of New York City with smoke and dust rising from the World Trade Center site."

(Text from Wiki)