deputy dog reports on a bit of whimsical road engineering in (where else?) Japan:
a few years ago in japan, members of the hokkaido industrial research institute started carving thousands of very precise grooves into nearby roads. the slightly loopy brainwave belonged to a mr. shinoda, a guy who accidentally cut a road in several places with a digger and then later drove over the damage in his car.
he realised that with some planning and time to kill he could create rows of grooves which, when driven over at a certain speed, would ‘play a tune’. . . . the grooves are between 6 and 12mm apart: the narrower the interval, the higher the pitch.
Video at the link. Believe me, it isn't pretty.