Opening

Opening is Disc 1, Track 2 on the Xenosaga Original Soundtrack and Disc 2, Track 1 on the album. The melody at 1:58 and (much more clearly) at 3:13 uses a motif from Dark Daybreak on the Xenogears Original Soundtrack.

It plays as the music in the second cutscene, when Shion prepares to dive into the Encephalon at the start of the game.