"On the sides of roads, especially on highways, you’ll often find groves. If you’re drowsy or not paying attention and happen onto them, you’ll be shocked into attention as a loud pitch fills your car. Here’s the idea: If we modulate the space in-between the grooves, we’ll be able to modulate the pitch that fills the car. The more grooves we put in a row, the longer the pitch will last. We now have pitch and duration. That’s enough the play melodies. Imagine driving down the road next to a winding river, and having the road itself play you the Blue Danube. Or going through the Rocky Mountains and have the road play American the Beautiful. And if we move the grooves to the center of the road, you won’t even have to drive off the road to hear it." - Ivan Zuzak