Halo 4 is the next title in the Halo series. Ever since it was announced, we have been able to grab onto a couple of music tracks that have been leaked.
The Halo 4 music has been promised to be different than the original trilogy's music by the Office of Halo Intelligence. It has also been confirmed that it will not be composed by Martin O'Donnell and Micheal Salvatori. Instead, it will be composed by Sotaro Tojima.
The first track was taken from the Halo 4 Teaser Trailer. It was composed by Neil Davidge. I wouldn't count this as an actual track considering it's just a one-time use song for the teaser, but I'll put this in here for your entertainment.
The second track was taken from the Halo 4 Teaser Trailer Director's Cut. The composer is assumed to be Sotaro Tojima or Neil Davidge.
The third track was taken from the 343 Industries ViDoc "Working at 343i". It was composed by Sotaro Tojima.
The fourth track was taken from the Halo 4 ViDoc "Making Halo 4: First Look". It was composed by Sotaro Tojima.
The next track I will post is from Metal Gear Solid 4. The songs are composed by Sotaro Tojima, so it might give you an idea of the upcoming music.
UPDATE: Leaked music directly from Halo Waypoint.
If anyone finds any other music I have missed, please post it in the comments below.