Remember, Celemony aren't the only people who can seem to extract sounds from a more complex recording and manipulate them. A couple of years ago on the Analogue Heaven mailing list were posted the two files below. One is Stairway To Heaven playing forwards while the sounds are all backwards, and the second is vice versa. These were done using free Soundhack software on the Mac. I didn't do them, so how it was accomplished, I don't know. Now's time for everyone to speculate how such a thing is possible. Might give more insight into how the Celemony people are pulling off their DSP magic.
(Song Forwards, Sounds Backwards)
(Song Backwards, Sounds Forwards)