You can’t deny that the music in this trailer is beautiful, and is essential to the delivery of the right mood to the audience. Music in films and games are design to do just that: get the mood across to the audience.
The composer for the Halo video game franchise is Martin O’Donnell, and he is an amazing composer. Because I’m a big gamer, I of course play Halo, and I appreciate much of the great music in the games. He talks about his inspirations, his use of various instruments, and his history in many of the interviews that I’ve seen, and it’s all greatly inspiring.
To finish, this piece of his is perhaps the most emotional piece of music ever composed for a video game.