The harmonica is by far my favorite instrument, I love the different types of music that can be played on it as well as the many different characters you find playing it. Recently I have been teaching myself how to play a harmonica and have been wondering the physics behind it. In each hole of the harmonica there lies a reed, all of which are different in size. When you breathe into the harp of the harmonica the reeds vibrate at different frequencies causing the different pitches you hear. Each reed is fastened to the reedplate with one screw, allowing the rest of the reed to vibrate freely. The harmonica can be very simple and some of it can be very complex. Once you become proficient at the harmonica you can learn how to bend notes and master the harmonica.