How many of you noticed this in the spell casting demonstration?

[Rydin]

In game development, the dev version is usually different from the gold/rtm version of the game. There's a possibility they're using an older version or a version that they may incorporate at some point (they could be re-mixing the soundtrack and the dev version uses the in-progress works.)

or its this

As far as the difference between the tracks... they do sound different

mainly due to different post processing applied to each

Also in-game music is mixed and/or mastered differently than OST versions

The OST is mixed more like what we are used to on the radio whereas the in game version is mixed to be played along with the games sound FX

For this particular example... the OST version was compressed more to raise the overall volume while the in game version has more dynamic range

The same thing happened with Guitar Hero: Metallica and the Death magnetic CD