Complex sentence: The game's opening theme was composed by Yasunori Mitsuda, who had previously worked with Kato on "Xenogears" and the "Chrono" series, with the in-game score being composed by Shunsuke Tsuchiya and Mariam Abounasser.
Split into simpler sentences: The game's opening theme was composed by Yasunori Mitsuda, who also worked with Kato on previous titles, such as "Xenogears" and the "Chrono" series. The in-game score was composed by Shunsuke Tsuchiya and Mariam Abounasser.