Harmonica (Fallout 3)

Harmonicas are stashed sparsely throughout the Capital Wasteland. They are useful as Rock-It Launcher ammunition and can be bartered for a small amount. They are somewhat rare, as there are maybe only about 10-20 in the whole game. Rarely, Feral Ghouls and Centaurs will have this item in their inventory. With the add-on Point Lookout you can find around 15 if you keep your eyes peeled.