They say audio is half the picture. It's true, more than half in my opinion. It determines the entire emotion of any scene. It can convey intensity, sympathy, anger, inspiration, happiness, dispair - you name it. Even silence can be a powerful weapon.
Take a look at this. Yes, the subject here is 2D video games but because of the music laid against it, it elicits a completely different emotional response. Many of you already do this, but I strongly encourage you to consider your audio choices even more. They can put your video onto a whole other level of connection for the audience or make it fall on its face.
Music by Michael Nyman from the Motion Picture score, "The Piano"