Vocal music
Vocal music is music performed by one or more singers, which are typically called songs, and which may be performed with or without instrumental accompaniment, in which singing provides the main focus of the piece. Vocal music is probably the oldest form of music since it does not require any instrument or equipment besides the voice. All musical cultures have some form of vocal music and there are many long-standing singing traditions throughout the world's cultures. Music which employs singing but does not feature it prominently is generally considered instrumental music. For example, some blues rock songs may have a short, simple call-and-response chorus, but the emphasis in the song is on the instrumental melodies and improvisation. Vocal music typically features sung words called lyrics, although there are notable examples of vocal music that are performed using non-linguistic syllables or noises, sometimes as musical onomatopoeia. A short piece of vocal music with lyrics is broadly termed a song, although, in classical music, terms such as aria are typically used.