Symphony No.9 in D minor Opus 125 Ludwig Van Beethoven
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Video Game Music - 15 great computer game scores
The Halo franchise is one of the most popular in video games history (as the queue in the photo suggests) and Martin O'Donnell's soundtrack is suitably blockbusting as well. In fact, the original soundtrack is still the best-selling video game soundtrack of all time. Try the main theme - it's gently choral with some serious orchestral clout (and electric guitar!).