Music is often a vital factor in making games as immersive and emotional as possible. It can turn a regular scene into a much more powerful one or even tell you something about the story with its tone (See SotC), so yes, music is definitely important.
However, it is not always crucial. There are kinds of games or scenes that would do better without background music. There are horror games that stay quiet the entire time, for example, because music would give away danger or just ruin the creepy atmosphere.
So if it fits into the game or scene and would overall improve it, then it should indeed contain good music made by TALENTED composers, because generic, boring music harms more than it helps.
If the game can or should do without, then it should do without.
Daystar Clarion said:
Oh and this one too. It captures the fact that you're battling an enormous beast perfectly as well.
Although all of them are good, obviously. And the after-battle song is incredible as well, because it tells so much about the story. Even changing it a little bit would completely destroy the entire scene. Man, I love SotC so much.