a cappella

A cappella — literally Italian for 'in the manner of the chapel' or 'in the chapel style' — means vocal music performed without instrumental accompaniment. The phrase combines the Italian preposition a (in the manner of, in the style of, from Latin ad) and cappella (chapel, small church, from Late Latin capella, originally a diminutive of capa, the cloak — specifically the cape of Saint Martin of Tours, which was carried as a relic and housed in a capella or oratory). The musical meaning develops from the practice of the medieval and Renaissance chapel choir, where voices sang the polyphonic sacred repertoire without independent instrumental parts — the voices were the entire musical apparatus.

The history of European choral music is in large part the history of what happens when voices are given or denied instrumental support. Medieval polyphony — the Gregorian chant tradition and the complex polyphonic motets of the Notre Dame school (c. 1160–1240) and the Ars Nova (c. 1310–1377) — was conceived for unaccompanied voices, though instruments sometimes doubled or supported vocal lines in performance. The Flemish and Franco-Flemish composers of the fifteenth and sixteenth centuries — Dufay, Ockeghem, Josquin des Prez, and later Palestrina — wrote polyphonic sacred music in which the independence of each voice line was a compositional ideal: a cappella performance revealed the intricate counterpoint in its purest form. Giovanni Pierluigi da Palestrina (c. 1525–1594), whose polyphonic masses and motets are the paradigm of Renaissance sacred style, wrote music that has been performed a cappella ever since, and his name is synonymous with the ideal of unaccompanied vocal purity.

The Reformation and Counter-Reformation transformed the place of music in Christian worship across Europe. The Council of Trent (1545–1563), the Catholic Church's response to the Protestant Reformation, debated whether complex polyphony was appropriate in sacred contexts at all — whether ornamentation and counterpoint obscured the words and distracted from devotion. The legend that Palestrina's Missa Papae Marcelli (c. 1562) saved polyphonic church music by demonstrating that its words could be heard clearly is almost certainly apocryphal, but it reflects a real anxiety of the era about the relationship between voices, instruments, and worship. The a cappella tradition was at the center of this debate.

In the twentieth and twenty-first centuries, a cappella has expanded far beyond its sacred origins. Barbershop quartet singing — the American tradition of four-part unaccompanied harmony, typically of sentimental songs — developed in the late nineteenth century and formalized into competitive organizations in the 1930s. Collegiate a cappella groups became a distinct American campus phenomenon beginning in the early twentieth century and growing dramatically from the 1980s onward. The television competition show Pitch Perfect (2012, as a film) and The Sing-Off brought collegiate a cappella to mass audiences. Contemporary a cappella groups perform everything from Bach to Radiohead using only their voices, including vocal percussion (beatboxing). The term has completely shed its chapel connotation in popular usage.