Soundtrack Leaked???

[Google]

I just downloaded a file fro alt.binaries.starwars called -

John_Williams_-_Star_Wars_Episode_III_The_Revenge_Of_The_Sith_-_Main_Title_Aproaching_The_Battle

is this authentic????
I've never heard this piece of music if its not genuine???
Anyone know if any of the other tracks have been leaked if its the real thing????