Requires 3 Persons, 2 metal balls with a piano wire or guitar string affixed to each, 1 violin bow.
2 people place the metal balls inside the rectum and then pace away from each other until wire is taut. The 3rd person 'plays' the string with the bow to create vibration and sound.
What'd you do this weekend?
Oh, nothing, just hung out with some friends and played the butt harp.