Apparently the original release (God.of.War.Ghost.of.Sparta.HD) was missing some music because of a misplacement of a folder.
You can fix this though without downloading the new release (God.of.War.Ghost.of.Sparta.HD.MUSIC.FIX).
Tutorial (Credits to ecnalab from PS3 iso):
- After installing the game use a FTP app or a file manager to access your Internal HDD.
- Go to /dev_hdd0/game/NPUA80636/USRDIR/data/
- Move the "music" folder to /dev_hdd0/game/NPUA80636/USRDIR/data/gos/
- After you've done that, you should have 4 folders "dialogs", "movies", "music", "packfiles" inside /dev_hdd0/game/NPUA80636/USRDIR/data/gos/
- You're done, no need to download the game again for the music to work.