The document discusses the Bulgarian kaval, a traditional woodwind instrument. It describes the kaval's structure, which consists of a wooden cylindrical tube with holes. The kaval is played by blowing air through pursed lips into the instrument at a 45 degree angle. It has three registers that allow it to play over two octaves. Different finger positions produce different tones and timbres. The kaval is an important part of Bulgarian folk music traditions and is played by many renowned Bulgarian musicians.