'in [the style of] the chapel'), less commonly spelled a capella in English,[2] is music performed by a singer or a singing group without instrumental accompaniment.

Recent evidence has shown that some of the early pieces by Palestrina, such as those written for the Sistine Chapel, were intended to be accompanied by an organ "doubling" some or all of the voices.

Five of Schutz's Historien were Easter pieces, and of these the latter three, which dealt with the passion from three different viewpoints, those of Matthew, Luke and John, were all done a cappella style.

Early Russian musika which started appearing in the late 17th century, in what was known as khorovïye kontsertï (choral concertos) made a cappella adaptations of Venetian-styled pieces, such as the treatise, Grammatika musikiyskaya (1675), by Nikolai Diletsky.

Weaving together Jewish and Greek thought, Philo promoted praise without instruments, and taught that "silent singing" (without even vocal chords) was better still.

The shofar is used by itself, without any vocal accompaniment, and is limited to a very strictly defined set of sounds and specific places in the synagogue service.

"[44][45] An a cappella tradition was begun in 1911 by F. Melius Christiansen, a music faculty member at St. Olaf College in Northfield, Minnesota.

The choirs typically range from 40 to 80 singers and are recognized for their efforts to perfect blend, intonation, phrasing and pitch in a large choral setting.

The Contemporary A Cappella Society (CASA) is a membership option for former students, whose funds support hosted competitions and events.

In July 1943, as a result of the American Federation of Musicians boycott of US recording studios, the a cappella vocal group The Song Spinners had a best-seller with "Comin' In on a Wing and a Prayer".

A cappella music attained renewed prominence from the late 1980s onward, spurred by the success of Top 40 recordings by artists such as The Manhattan Transfer, Bobby McFerrin, Huey Lewis and the News, All-4-One, The Nylons, Backstreet Boys, Boyz II Men, and *NSYNC.

Examples of such professional groups include Straight No Chaser, Pentatonix, The House Jacks, Rockapella, Mosaic, Home Free and M-pact.

[56] in 2015, an a cappella version of Jerusalem by multi-instrumentalist Jacob Collier was selected for Beats by Dre "The Game Starts Here" for the England Rugby World Cup campaign.

Perfect Harmony features the hit music of The Jackson 5, Pat Benatar, Billy Idol, Marvin Gaye, Scandal, Tiffany, The Romantics, The Pretenders, The Temptations, The Contours, The Commodores, Tommy James & the Shondells and The Partridge Family, and has been compared to a cross between Altar Boyz and The 25th Annual Putnam County Spelling Bee.

Set primarily in the New York City subway system its score features an eclectic mix of musical genres (including jazz, hip hop, Latin, rock, and country).

Today the BHS has about 22,000 members in approximately 800 chapters across the United States and Canada,[66][67] and the barbershop style has spread around the world with organizations in many other countries.

The popularity of a cappella among high schools and amateurs was revived by television shows and movies such as Glee and Pitch Perfect.

[70] However, the de facto national anthem of Afghanistan is an a cappella nasheed, as musical instruments are virtually banned as corrupting and un-Islamic.

[71] The first a cappella group in Iran is the Damour Vocal Band, which was able to perform on national television despite a ban on women singing.

[77] The European a cappella tradition is especially strong in the countries around the Baltic and perhaps most so in Sweden as described by Richard Sparks in his doctoral thesis The Swedish Choral Miracle in 2000.

[79][additional citation(s) needed] The longest continuously singing group is probably The Whiffenpoofs of Yale University,[80] which was formed in 1909 and once included Cole Porter as a member.

The show featured eight a cappella groups from the United States and Puerto Rico vying for the prize of $100,000 and a recording contract with Epic Records/Sony Music.

The show was judged by Ben Folds, Shawn Stockman, and Nicole Scherzinger and was won by an all-male group from Puerto Rico called Nota.

The show returned for a second, third, fourth, and fifth season, won by Committed, Pentatonix, Home Free, and The Melodores from Vanderbilt University respectively.

According to ethnomusicologist Joshua S. Dunchan, "BOCA carries considerable cache and respect within the field despite the appearance of other compilations in part, perhaps, because of its longevity and the prestige of the individuals behind it.

"[84] Collegiate a cappella groups may also submit their tracks to Voices Only, a two-disc series released at the beginning of each school year.

WACA offered another medium for women's voices to receive recognition and released an album every year from 2014 to 2019, featuring female-identifying groups from across the United States.

[91] The first winner of the championship title was Swaram A Cappella at Texas A&M University, who won 1st place at All-American Awaaz in 2017 in New York City[92] as well as in 2018 in Chicago.

One of the earliest 20th century practitioners of this method were The Mills Brothers whose early recordings of the 1930s clearly stated on the label that all instrumentation was done vocally.

More recently, "Twilight Zone" by 2 Unlimited was sung a cappella to the instrumentation on the comedy television series Tompkins Square.