The apito (whistle) is an instrument which belongs to the aerophone family. Almost every culture in the world has its own version, as this instrument is used both for musical purposes and to demonstrate authority and leadership, generally by traffic police and referees.
For the oral tradition, it is carved out of wood or another similar natural material, but whistles are also made out of metal, ceramic and plastic. The sound is produced as air passes along one edge and begins to vibrate.
Some whistles have holes on the side, which are covered with the fingers to produce different tones, and controlled by the player to change the duration and intensity of the sound. There are a variety of techniques for producing different rhythms and timbres on this instrument; these techniques produce loud and soft, long and short, and open and closed sounds.
In indigenous culture, whistles are used in different types of rituals to invoke spiritual beings and entities, generally by imitating the sounds of different birds. In Brazilian pop music, they are widely used by drum musical conductors in samba schools to play rhythmic patterns, announce the beginning, the end, or a new section, and to play a repetitive pattern along with the rhythmic group.