The harmonica, also called harp, French harp, and mouth organ is a free reed wind instrument used primarily in blues and American folk music, jazz, country music, and rock and roll. It is played by blowing air into it or drawing air out by placing lips over individual holes (reed chambers) or multiple holes. The pressure caused by blowing or drawing air into the reed chambers causes a reed or multiple reeds to vibrate up and down creating sound. Each chamber has multiple, variable-tuned brass or bronze reeds, which are secured at one end and loose on the other end, with the loose end vibrating and creating sound.