My little bro is a big video game nut, but in the last 3 years or so, he's been developing a tremendous musical talent. It's enough that he plays guitar and saxophone, but he's also taken to composing original soundtrack music for a hypothetical videogame he's been putting together in his mind (conceptually anyway). He was always a fan of my own original songs, and he really wanted to do what I was doing. So- with no guidance or instruction from me- he started teaching himself how to work FL Studio on our computer. He started out recreating entire arrangements of classical tunes that his school band was playing, amazingly able to remember every instrument's part all the way through. Example:
http://www.furaffinity.net/view/10027493/
(I helped a tiny bit on that one, only by adding a part for the strings to give it a little more punch).
But then he started trying to come up with his own arrangements and scores. His first few were rough, but showed potential, and improved quickly from one to the next.
This is his latest- note, all his own work- a boss battle theme for a character called "The Duke". I didn't like what he started out with when he first showed me what he was working on, but the song evolved in ways I would never have expected. Clever use of instruments, brilliant harmonies, and from about the 2 minute mark till the end, it takes a dramatic turn that- for a 13 year old- totally blows me away. Enjoy! Comments are much appreciated (more than faves even!)

Side note- he's also got me contributing to the soundtrack a bit. Here's one I made- specifically for his game idea- for another boss battle:
http://www.furaffinity.net/view/12539164/
[The killer for me is that, despite having only a year's experience, his original scores are better than my compositions were after I'd been at it for 3 years! I'm 23 now, and I've been composing for almost 7 years, but when lil' bro started clicking aimlessly on the PC, he took off like a rocket. I'm afraid soon he'll be on par with me or better! He's even starting to figure out some of the production techniques that took me ages to understand well enough to use them].