A cappella is a style of vocal music performed without instrumental accompaniment. Singers use their voices to create melodies, harmonies, and rhythms, often imitating instruments or producing vocal percussion. This form of music can be found in various genres, including classical, jazz, and pop. A cappella groups can range from small ensembles to large choirs, and they often perform arrangements of popular songs or original compositions. Notable examples of a cappella groups include Pentatonix and The King's Singers. This musical style emphasizes vocal skill and creativity, allowing singers to showcase their talents in unique ways.