I used to think I was a pretty big Legend of Zelda fan, and yes, I am in possession of a functioning Ocarina that I am able to make halfway decent music with. However, YouTuber Sufficiently Advanced has taken both his Zelda love and Ocarina skills to the next level, with the assistance of a Raspberry Pi and other assorted items.
Using tunes made popular by Ocarina of Time, Sufficiently Advanced can unlock his doors, change his thermostat, find his phone, and more. Want to turn the lights on? Sun's Song. Unlock your trusty steed (car)? Rock out to Epona's Song.
It's an impressive video, and makes me more than a little jealous that I didn't think of it first.