My Rube Goldberg Machine is the automatic piano player when the marble hits the car the car will hit the hot wheels sling shot which sets a pulley to drop a lock on the button that makes the song play. It took 29 takes maybe 32 not sure really i repeated the same number 3 times! Often it was the same thing that didn’t work and the thing was the meant to be the easiest thing in the whole machine. There was a lot of domino setting up and i got really frustrated and started to pack the machine up three times but i eventually got there in the end. I think machine is great for when you want some tunes because it changes every time to a different song! I am now going to start working on a grape feeder machine in the holidays! I can’t wait to get started!