"Open Your Heart" is the main theme song of Sonic Adventure, performed by Crush 40. It is of a hard rock genre. Remixes have been made featuring Bentley Jones and K-Klub. The song was composed by Jun Senoue, who also took lead guitar duties and had already been working as the head music director for Sonic and Sega related games for several years. In the early demo version of the song, Senoue even provided the vocals for the song. Eventually, Hardline frontman, Johnny Gioeli, was chosen as the lead vocalist, forming the group that would later become Crush 40 (they had not been officially named Crush 40 until years later). Also involved in the song are Naoto Shibata on bass and Hirotsugu Homma on drums. They each joined a separate band later on, Loudness and Anthem, respectively.