The Little Metronome That Wouldn't

Take a metronome. Then take another. Then another. Set them ticking at different times. Look. Lift. (That's the key part.) Watch. Then Laugh. Because you will be dumbfounded.

Source: http://www.npr.org/blogs/krulwich/2013/05/17/184815141/the-little-metronome-that-wouldnt?ft=1&f=1007

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