This is the Wintergarten Marble Machine.
It uses 2000 metal marbles to make music!
It’s INCREDIBLE. You HAVE to watch it in action:
In the video, that’s Martin Molin of the Swedish band Wintergatan cranking this cool music machine. He created this amazing marble-filled invention (it took over a year!) and plans to automate it so it can act as an extra musician in the band.
Has he LOST his MARBLES?! 😉