When I was playing the trumpet the other day in band, I realized that I was using physics. As I blow into the trumpet it creates vibrations that move through the air ways of the instrument. The waves come out through the other end of the trumpet and generate a sound. if I apply more force when I create the vibrations then I would be increasing the amplitude. If I press down certain keys then I can change the path that the air waves take and change the pitch of the wave which would change the frequency.