Medieval popes once tried to ban singing in more than one melody
In 1322 Pope John XXII banished polyphony from the liturgy, and two years later he issued a bull warning against its unseemly novelties. Critics called harmony frivolous and lascivious, and complained it buried the sacred words. Yet the practice of weaving several independent melodies together had already taken root and would shape Western music.
Polyphony means two or more independent melodic lines sounding at once, unlike a single voice or a tune with chordal backing. The oldest written European examples are two treatises from around 900, Musica enchiriadis and Scolica enchiriadis, which show singers how to improvise a second voice moving note against note with a chant in parallel octaves, fifths and fourths. The Winchester Troper of about 1000 is usually counted as the oldest notated polyphony for chant, though it gives neither exact pitches nor rhythms. A two-part antiphon to Saint Boniface found in the British Library may be older still.
In the twelfth century Léonin and Pérotin expanded organum, adding third and fourth voices. By the thirteenth, composers were hiding the chant beneath secular tunes, sometimes singing love poems over sacred texts. The six-part English round Sumer is icumen in dates from around 1240. The papal court at Avignon, a lively centre of secular music, blurred the line further, which is what alarmed John XXII, though Clement VI happily indulged. Guillaume de Machaut's Messe de Nostre Dame of 1364 is the oldest surviving mass setting that can be credited to one composer.
Much later, English west gallery singers developed polyphonic fuguing tunes by the mid-eighteenth century, and emigrants carried them to America in shape-note books such as The Sacred Harp. The style survived in the rural South and has since spread as far as Germany, Poland and Australia.
Beyond the church, polyphonic singing is most widespread in sub-Saharan Africa, Europe and Oceania. In southern Albania, Tosk singers hold a continuous drone on the syllable e using staggered breathing, while Lab singers sometimes make the drone rhythmic. Two rival theories explain such traditions: one sees polyphony growing out of simple monophonic singing as culture developed, the other ties it to early hominid defence and sees it slowly vanishing.
Source: Polyphony
