Ars Nova~break-in

 is a track in Xenosaga II to III: A Missing Year. Despite its name, it is unrelated to and. Its melody is a highly modified version of my long forgotten cloistered sleep (unreleased work of Xenosaga): while the actual notes are different, the chord progression and melodic contour are the same.

It plays in Chapter 4 when Jin goes to the Scientia lair to ask for their help in finding Shion.