His World

His World is Sonic's theme from Sonic the Hedgehog and was performed by Matty Lewis and Ali Tabatabaee from the rock band Zebrahead. Due to the amount of times this song was used in trailers and in-game, His World most likely is the game's main theme.

Versions
Multiple variations of the song have been used, both in-game and in promotional media/trailers. They are the following:


 * Instrumental Version: The first version of the song used in the first trailer, the TGS 2006 trailer, and a few in-game cut scenes featuring Sonic.


 * Vocal Version: A much more rock-oriented version with lyrics. There is also rapping at various sections of the song. A shortened version can be found here.


 * Orchestral Version: Similar to the instrumental version but with varying instruments. Played during the second half of the climatic final battle between Super Sonic, Super Shadow, Super Silver and Solaris.

Trivia
This is the first time a main theme hasn't been done by Crush 40. Sega chose the band over Crush 40 due to Zebrahead's growing popularity in Japan.