A cappella (also spelled "acapella") is a style of vocal performance without instruments. The word means "from the chapel" in Italian, as a cappella takes its roots in early religious music. A cappella singing has been used in Christian, Islamic, and Jewish religious music for many centuries; references to Jewish a cappella chanting date back as early as 20 BCE. Today, the term "a cappella" encompasses many different secular styles, including doo-wop, the barbershop quartet, and the pop a cappella common on many college campuses today.
The history of a cappella in religious ritual is long and deliberate, as many sacred texts in both the Judeo-Christian and the Islamic tradition can be interpreted as forbidding instruments in worship. Christian musical worship was traditionally a cappella. Instruments were not introduced into the church until 670 AD, when Pope Vitalian brought an organ to his cathedral, and many Christian pop a cappella groups remain popular today. For Jews, the use of musical instruments is prohibited on the Sabbath, and informal Jewish worship often includes songs sung a cappella, known as "zemirot." The Muslim religion also has a long tradition of unaccompanied worship songs, known as "nasheed."
Barbershop music, one of the few exclusively American vocal styles, is characterized by its taut, consonant four-part harmonies and ringing overtones. The word "barbershop" was first used to describe this a cappella harmony style in the 1910 song, "Play That Barbershop Chord." Early barbershop music was closely associated with African-American gospel quartets like the Mills Brothers. In the '40s, barbershop music became widely popular, and in 1954, the Chordettes brought barbershop into the pop mainstream with their song "Mr. Sandman."
After the middle of the century, bands like the Persuasions and Manhattan Transfer brought a cappella and a cappella elements closer to the center of pop music. Songs such as "The Lion Sleeps Tonight," released as a debut single in 1981 by the Nylons, became wildly popular. Billy Joel's "nearly a cappella" song "For the Longest Time" became a hit in 1983. Paul Simon's "Graceland," which features a South African a cappella ensemble, won a Grammy for Best Album in 1986; Rockapella was formed later that year. Boyz II Men's "It's So Hard to Say Goodbye to Yesterday," which is entirely a cappella, became an enormous hit in 1991 and remained on the Billboard charts for 133 weeks.
The tradition of collegiate a cappella begins in 1909 with the founding of the Yale Whiffenpoofs, the longest continuously existing group in the country. Until recently, college a cappella was traditional; groups often sang college-specific songs and maintained classic, revolving repertoires. In the '90s, collegiate a cappella began to turn towards a pop audience. The new style revolved around the imitation of rock instruments, and vocal percussion (beatboxing) became essential. Today there are thousands of college a cappella groups in the United States; there are also societies that hold a cappella championships and recording awards. Alumnae of college a cappella groups include Cole Porter, Sara Bareilles, and John Legend.
Today, there are several all-a cappella record labels, including Primarily A Cappella and Hot Lips Records. A cappella elements have been used in every musical genre, including punk, hip hop, and electronica. The Recorded A Cappella Review Board (RARB) reviews over 100 albums a year, and hosts a discussion forum with over 20,000 articles to date. Interest in mainstream, popular a cappella has spread to Africa and India.