I found this picture on the website of the Dortignac family and thought it was fantastic. Look carefully and see if you can connect each hand to its correct person!
This reminds me of a concert my family went to last weekend that featured similar musical acrobatics. Here's my brother, Seth's description of it: "For one song [the hammered dulcimer player] said he would play the harmonica, hammered dulcimer and guitar all at once! He started with the dulcimer and harmonica. Then another man came up behind him and started playing the guitar! Afterward the guitar player lifted up his arms and scratched the other guy’s head like they were the other guy’s arms. It was really funny."