mood related/enforcing music.

Not ridiculous at all. I just gave a brief speech to an extracurricular group I'm in about movie soundtracks and how music elicits emotion. There's actual a lot behind music psychology.

At an insanely basic level, music designed to elicit emotion replicates sounds associated with human emotion - crying, laughter, etc. Fast music sounds happy because happy people generally talk quickly and with excitement. The opposite for slow music. A violin can be made to sound like screaming or it can be played as a fiddle, a very happy way to play. There's also a bunch of music theory behind major and minor keys and dissonance and a bunch of stuff I don't know anything about.

http://www.ted.com/talks/benjamin_zander...ssion.html
A good TED talk mildly related. With an excellent little part at 8:40

Some other related videos:
A comparison of ways to play Happy Birthday To You
Bobby McFerrin (Don't Worry Be Happy) shows the universality of the pentatonic scale

Some of my own examples:
Samuel Barber's Adagio for Strings, voted the saddest song in existence in a BBC poll.
[video=youtube;lV3SHBFyDZM]https://www.youtube.com/watch?v=lV3SHBFyDZM[/video]
Victory music!
[video=youtube;GopzpFJm4LQ]https://www.youtube.com/watch?v=GopzpFJm4LQ[/video]
Hans Zimmer is awesome in general. Like audible dread. Heavy on the mind and ears.
[video=youtube;imamcajBEJs]https://www.youtube.com/watch?v=imamcajBEJs[/video]

One of my favorite songs. Period. The title is the only word that really fleshes out the feeling it gives me. 'Arise'
[video=youtube;IJWgUUc-oNE]https://www.youtube.com/watch?v=IJWgUUc-oNE[/video]