As with "Sonic Adventure", Jun Senoue served as sound director and lead composer. Additional music was contributed by Fumie Kumatani, Tomoya Ohtani, and Kenichi Tokoi. The soundtrack is primarily melodic rock, with some hip-hop and orchestral tracks. As in "Adventure", each character has a musical theme. The game features performances by returning vocalists Tony Harnell, Ted Poley, Marlon Saunders, Nikki Gregoroff and Johnny Gioeli, and new vocalists Tabitha Fair, Todd Cooper, Paul Shortino, Everett Bradley, Kaz Silver and Hunnid-P. Crush 40 (consisting of Senoue and Gioeli) debuted on the game's main theme, "Live & Learn". Production of the music lasted from April 2000 to February 2001; after this Senoue, along with others, created sound effects.