This is the keyboard catapult! all you need is some bbs, a rubber band, and a keyboard leg.
first, you wrap the rubber band around the keyboard leg, making sure the smaller section rests on the thicker layer of band. Don't forget to put a twist in front of the smaller section.
And there you have it!! The keyboard leg catapult. Tip: you might want to attach a small slice of wood at the front part so it is angled up.