Can't stop the music in your head? Get it down on paper. Become a Composer.
This is your chance to start a life writing film scores, soundtracks, even some ground-breaking stuff for bands.
You could become free and freelance, or full-time - possibly teaching composition at schools or developing soundtracks for multi-media companies.
And to make it as a Composer? Just complete a sub-major in Composition, with electives in Digital Music and Performance.