In the woods of Kyushu, Japan, a team of filmmakers built a massive xylophone running down a long, steady slope. They then rolled a wooden ball down the thing, striking each tuned bar only once, and it played Bach’s “Jesu, Joy of Man’s Desiring.” (If you’re not familiar with the tune, here’s an orchestral performance.) This is truly impressive engineering, filmmaking, and music!

via Mental Floss

Click here to continue reading and to watch video