I OWN NOTHING! Music is by John WIlliams and is from the Star Wars Episode II: Attack of the Clones and Star Wars Episode III: Revenge of the Sith.
I actually really had a hard time deciding on what to title this video. This theme is first introduced in Attack of the Clones when Anakin is in the arena and hops on top of the reek. That's the only time it plays in episode 2.
This theme also plays during Volume 2 in the Star Wars Clone Wars 2003 mini-series when the Separatist Droid Army Invades the outer rim worlds.
Finally, the theme plays in Star Wars Episode III: Revenge of the Sith a few times. During the Battle of Kashyyyk and Utapau. It is also remembered for being the music that plays during Anakin's March on the Jedi Temple.
Because of all the different appearances this theme is known by many different names: The Arena Theme, CIS Theme, Droid Army Theme, March on the Jedi Temple Theme, Order 66 Theme, Clone Army Theme. I couldn't decide which to pick so I just chose the name I liked most. Enjoy!