The Soundtrack of Xenosaga Episode I is a soundtrack composed by Yasunori Mitsuda, and many of the songs have been performed by the London Philharmonic Orchestra. Because Yasunori Mitsuda composed the soundtrack for Xenogears and Xenosaga Episode I, there are some stylistic similarities between the scores. Joanne Hogg, who also performed Small Two of Pieces in Xenogears returns to sing Kokoro and Pain. Fans of the main theme from Xenogears can enjoy 26 seconds of carefully incorporated music into the track Opening at 3:09.