A cappella
Music performed a cappella ( AH kə-PEL-ə, UK also AK ə-PEL-ə; Italian: [a kkapˈpɛlla]; lit. 'in [the style of] the chapel'), less commonly spelled a capella in English, is music performed by a singer or a singing group without instrumental accompaniment. The term a cappella was originally intended to differentiate between Renaissance polyphonic and Baroque concertato musical styles.