The document discusses the clarinet, the author's favorite musical instrument. The clarinet is a woodwind instrument from the family of wind instruments. It is agile like the flute and can produce any sound. The clarinet is composed of a glass mouthpiece with a reed attached by a clamp, a wooden cylindrical tube with holes that are covered by the fingers, and is related to other instruments like the saxophone, oboe, and chalumeau. The document also notes the playing range and that the clarinet is made of wood.