butt flute

The act of putting different fingers over your anus while farting.

The Juction City Butt Flute (JCBF), is a primitive musical instrument, that can be easily made by simply inserting two blades of grass into one's anus. When the musician farts, the hot gas causes the blades of grass to vibrate, which generates a "tooooooo" sound. The pitch and cadence of the sound is a function of the quantity and moisture content of the fart expelled, as well as the forcefulnes of the expulsion. It is widely believed that the JCBF was invented in Junction City, Kansas by street urchins in the 1970s.