The oldest of all musical instruments, the voice produces sound when air from the lungs vibrates the vocal chords in the throat. The air in the hollow spaces of the chest, throat and mouth vibrates and amplifies the sound of the voice. The vibrations of the vocal chords resonate in the cavities of both the chest (in the lower register) and the head (in the upper register). Loose vocal cords produce low notes, and tight vocal cords produce high notes. The singer automatically adjusts the shapes and sizes of these cavities to produce the required notes.
As the singer is his or her own instrument, the voice is never altogether distanced from the personality. A trained singer can easily combine the power of the voice with emotional nuances to weave a spell over the listener.
The human voice is also extremely flexible, lending itself to a wide genre of music – from classically trained opera singers, to the mellow sounds of the blues-lounge singer.
The voice can be divided into 4 pitch ranges : Soprano, Alto, Tenor, Bass