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, pop, and jazz, and is popular in both formal and informal settings. Groups or choirs performing a cappella often arrange songs to highlight vocal skills and creativity. Notable examples include The King's Singers and Pentatonix, who have gained fame for their innovative arrangements and performances. A cappella is also a common feature in competitions and festivals, showcasing the talent of vocalists.