How a bongo makes sound

The bongos make sound when you hit the instrument and that causes a sound wave. A sound wave is when you hit the instrument and that makes it vibrate. To make a higher note you have to tighten the edges and to make a lower note you have to loosen the edges. On the bongos there is a bigger drum and a smaller drum that is joint together. When you hit the bigger drum it is louder than when you hit the smaller drum.