A barbershop quartet is a music group consisting of four singers harmonizing in a cappella style. Synonyms for this term include quartet singers, barbershop singers, four-part harmony group, and vocal harmony ensemble. This genre of music originated in the late 19th century and gained popularity in the early 20th century. Nowadays, contemporary barbershop quartets add a modern flavor to their music while retaining the classic sound. Some examples of popular modern barbershop quartets are Vocal Spectrum, Crossroads, and Max Q. Whatever the name, barbershop quartets continue to entertain and captivate audiences with their exceptional vocal harmonies.