* The frantic drumming at the end of "[[Piggy]]" played by Reznor himself—his first and only attempt at live drumming on a record, and one of the few "live" drum performances on the album ([[Stephen Perkins]] on "[[I Do Not Want This]]," [[Andy Kubiszewski]] on "[[The Downward Spiral (song)|The Downward Spiral]]," and [[Chris Vrenna]] on "[[Hurt]]"). He states that it was from him testing the mic setup in studio, but he liked the sound too much to not include it. [http://www.9inchnails.com/articles/articles.php?id=6]
* "[[Closer]]" uses a heavily modified sample of a kick drum from the song "Nightclubbing" from ''The Idiot'' album by Iggy Pop. [http://www.9inchnails.com/articles/articles.php?id=6]
* "[[A Warm Place]]" is based on the melody from [[David Bowie]]'s 1980 single "Crystal Japan.". Some hear it as a complete rip-off, while others argue that from a music theory point of view that the structure has significant differences.
*The looping female voice that appears on "[[Reptile]]" (approx. 5:06) is from the 1974 film ''The Texas Chain Saw Massacre'' (although some people believe that it is from the film ''Nekromantik''). The strange mechanical sound before the drums start can be found in the movie ''Leviathan'' and the other sounds during all the song are found in ''Aliens'' (the escape in the vessel).