Cannon fire is an audio experiment that produces a series of crackles and bangs like gunfire.
It is a good example of catalysis. You set light to a mixture of ethanol and hydrogen peroxide. It burns gently and then you sprinkle on some crystals of potassium VII manganate. This catalyses the breakdown of hydrogen peroxide to produce oxygen, leading to some exciting, loud bangs as that causes a rapid increase in the rate of burning of the ethanol.