Quartet (noun)

A group of four people, especially musicians, performing together.

Origin:

Mid 17th century: from italian quartetto, from quarto 'a fourth', from latin quartus.

Examples:

1. The string quartet performed a classical piece at the concert.
2. The quartet's harmonious playing was a highlight of the evening.
3. The vocal quartet sang a beautiful acapella arrangement.
4. The jazz quartet entertained the audience with their improvisation.
5. The brass quartet added a lively touch to the parade with their music.