Multitracks for two extra songs, "[[37 Ghosts]]" and "[[38 Ghosts]]", were found on the data disc that came as part of the deluxe and limited edition releases. "38 Ghosts" is very similar to "[[Demon Seed]]".
===''Ghosts I-IV '' Discussion===
The Japanese edition of the CD set comes with a bonus 3rd disc featuring four commentary tracks by Reznor.