Unused Soundtrack Songs

For some strange reason it confused me to find out that artists would write songs specifically for a movie. Maybe I thought that they conveniently came out with a song just around the time a movie was coming out and guy in charge of music was like 'Oh my goodness. That would go perfectly with our movie.'

I was reading an article in a magazine about the music for the Hunger Games movie and it had a few of the artists talking about what they were trying to convey in their song and what parts of the book they took from for inspiration. After thinking about it a bit I thought that it made sense. Big movies like this can afford to have someone write them a song especially for them where as someone like me, who might have just enough to pull off a very amateur looking YouTube video, would just have to hope that they could find something that would make sense to everyone else too. Duh, Sarah.

Anyways, after I saw Hunger Games and kept hearing Taylor Swift's Eyes Wide Open on the radio, which is on the Hunger Games soundtrack, I realized that I didn't remember hearing the song use anywhere in the actual movie. Am I wrong?

It just seems that a sound track is suppose to be music that was used in the movie, right? Otherwise it's kind of a CD based on a book. I don't know, I haven't made enough movies to know better yet. Lol.

Would you have the songs you want for your soundtrack in your movie? Does it matter? Who would you ask to write a song for you?