Remember the Line Rider video that was synced to "Hall of the Mountain King"? That took a lot of work, but now imagine how much work went into synchronizing a real-world marble run to classical music! The same artist, YouTuber DoodleChaos, used Tchaikovsky's "Waltz of the Flowers" to design this intricate marble run.
It uses steel balls, magnets, dominos, levers, gravity, and exquisite timing as it builds to a musical climax. There's even a fidget spinner thrown in for good measure. Like the waltz, this chain reaction is a thing of beauty. -via Digg