The music in Ys VI is good, as is the game.
The only Ys release for the PS2 that's been localized in the west is Ys VI. Then there are the Taito made remakes of Ys III and Ys IV. The Ys III remake seems to be more or less a straight port with bumped-up graphics and so - as apposed to Oath in Felghana. And their Ys IV release seems to be some sort of combination of the SNES game Ys IV: Mask of the Sun and the PC Engine's Ys IV: Dawn of Ys. Eitherway, neither have been translated.
You can pick up Ys VI at
dvdboxoffice for example. (just make sure you can play imports first =p)
Jam it back in, in the dark.