These roads are in Hokkaido, Wakayama, Shizuoka and Gunma regions of Japan, and all play different tunes.
This works as a speeding alert sign, along with keeping drivers awake while driving. Besides road signs, all the roads are marked by musical notes that are painted on the surface of the road. These signs alert motorists of the incoming musical tune. Since these grooves are set on the side of the road and not in the middle, drivers have the option to either go over them or completely avoid them.
To listen to the musical notes, motorists need to keep the car windows closed and drive at 28 m/hr, keeping one wheel of the vehicle over the grooves. If you drive too fast over it, the sound will come out as a tape on fast forward but if you go slow or too slow, there will be music.
There are several hit Japanese songs that play for motorists and it looks like the idea is already a hit among tourists, who have been sharing their videos on various social media platforms.