This is a worthwhile video demonstration of the LEGO Mindstorms guitar playing robot built by engineer fastythefastcat. The machine is capable of both strumming the guitar and holding different chords. In this video it plays a cover of Of Monsters And Men's Little Talks. It is most impressive. The machine does make a fair amount of noise though. If you close your eyes and listen to the video it sounds like a real human guitarist playing while two robots have sex in the background. Now you won't be able to NOT think of that when you listen to it. Consider that my gift to you. "I don't want it." Regift it then, I'm not taking it back.
Keep going for the video demo, as well as a closer look at how the machine was built.
Thanks to Anil, who yelled FREEBIRD at his monitor for the whole four minutes but the robot refused to play it.