Evening /vp/,

I'm not so familiar with any pokemon game after red/blue but I just stumbled over this lavender town myth, that there was a ghost scribbled into the soundtrack's frequencies over time.

I'm doing a lot of signal processing stuff and I thought this was pretty fucking cool, but the ghost is not in the original red/blue song.

Can you tell me which game version's song this video uses?
http://www.youtube.com/watch?v=aoraDiyFxxg