The single unaccompanied line of sung Latin prayer from which the entire edifice of Western music — its polyphony, its staff, its very way of writing sound down — was raised.
History of Early Music · No. 01 — The Foundations
Plainchant (Latin cantus planus, "level song") is the body of monophonic, unaccompanied sacred song of the Western Church, sung to Latin texts in free, speech-like rhythm. Its largest and most famous dialect is Gregorian chant. For roughly a thousand years it was the music of Western Christendom.
A single melodic line, no harmony and no accompaniment — everyone sings the same tune in unison.
Texts drawn from the Psalms, scripture and the liturgy of the Mass and Divine Office.
No fixed metre or bar-lines: the rhythm follows the natural flow of the Latin words.
Built not on major/minor keys but on the eight church modes, each with its own colour.
"Plainchant" and "plainsong" are English synonyms; "Gregorian chant" names the specific Roman-Frankish repertory codified c. 800–900.
Tradition holds that the Holy Spirit, as a dove, dictated the chants to Pope Gregory the Great (c. 540–604) — a founding myth painted for centuries. The historical reality is later and more political: the repertory was assembled under the Carolingian kings, who fused Roman chant with the Gallican chant of Francia to bind the empire in one liturgy.
Every chant lives in one of eight modes — scales defined by a final (the note the melody rests on) and a reciting tone (the note psalms hover around). Each final has an authentic mode (melody sits above the final) and a plagal mode (melody sits around it).
Synthesised voice · listen for the different "flavour" of the semitone placement in each mode
Chant sets its words in three densities. The number of notes per syllable tells you the chant's function and solemnity — the more festive the moment, the more the voice blossoms into melisma.
One note per syllable. Plain, direct — used for psalm tones, hymns and the Credo where the text is long.
A small group (2–5 notes) per syllable. The everyday texture of antiphons and introits.
Many notes — sometimes dozens — on a single syllable. Ecstatic; reserved for Graduals, Alleluias and the great feasts.
A free-rhythm melisma on the syllable "e‑lei‑son", resting on the final D — synthesised single voice
The earliest chant signs — neumes (from Greek neuma, "gesture") — were written above the words around 900 CE. At first they only sketched the shape of the melody: up, down, together. Each neume shows how many notes fall on one syllable and which way the voice moves.
How to read them: a neume sits over the syllable it decorates. Read left to right; higher on the page = higher in pitch. A single shape can carry one note or a whole cluster — but early neumes gave no exact pitch and no rhythm. You had to know the tune already.
Around 1030, the Benedictine monk Guido of Arezzo (c. 991 – after 1033) solved the great problem: he ruled horizontal lines across the page, each a fixed pitch, and placed the neumes on and between them. A singer could now read an unfamiliar melody at sight — Guido boasted he could train a singer in days, not years.
He also named the notes. Taking the hymn Ut queant laxis, whose six phrases each begin a step higher, he drew out the syllables Ut–Re–Mi–Fa–Sol–La — the ancestors of do-re-mi and of solfège itself.
Ut(C) · Re(D) · Mi(E) · Fa(F) · Sol(G) · La(A) — each phrase-head of the hymn climbs one degree of the hexachord
By the 12th–13th centuries neumes had hardened into square notation on a four-line staff. This is the notation you still see in a modern chant book. Here is how to decode it.
The C-clef (or F-clef) names one line. Every other pitch is read relative to it — the staff can sit anywhere.
Squares grouped together belong to one syllable. Read a stacked group bottom-to-top, a spread group left-to-right.
There is none written. Notes are broadly equal; the words and phrasing shape the flow. No bar-lines.
The little mark at a line's end predicts the first note of the next line — a page-turn cue.
Chant is not concert music — it is the sung skeleton of two daily cycles of worship. Knowing where a chant belongs tells you its shape and style.
Ordinary (same text every day): Kyrie · Gloria · Credo · Sanctus · Agnus Dei — the movements later composers would set in polyphony.
Proper (changes with the feast): Introit · Gradual · Alleluia or Tract · Offertory · Communion.
Eight prayer "hours" from Matins to Compline, sung by monks and nuns through the day and night.
Its music: psalm tones, antiphons framing the psalms, responsories, and hymns — including the great Marian antiphon Salve Regina.
The Mass Ordinary is the seed of a thousand years of composition: every Mass by Machaut, Josquin, Palestrina or Byrd sets these same five texts.
The "Day of Wrath" sequence of the Requiem (13th c., attributed to Thomas of Celano). Its stark Mode I melody has haunted composers from Berlioz to film scores ever since.
The hymn to the Holy Spirit, sung at Pentecost and ordinations — quoted by Mahler in his Eighth Symphony.
The Easter sequence — a sung dialogue at the empty tomb, and a seed of liturgical drama.
Marian and Advent melodies still sung today, showing how deeply chant remains in the living Church.
Sing a chant while a second voice holds a low drone, and you glimpse the future. In the great churches, singers began to double the chant at a fixed interval — a fourth or a fifth below — and Western polyphony was born. That story continues at Notre-Dame with Léonin and Pérotin.
The same melody: first over a sustained drone, then shadowed a pure fifth below — pure Pythagorean tuning makes the fifths ring
Historically chant was sung unaccompanied; the drone is a performance convention that vividly demonstrates how a single line grows a harmony.
Everything we know of chant survives in hand-copied books. Comparing them let 19th-century scholars recover melodies that centuries of local habit had corrupted.
c. 900–930. The oldest neumed sources; their subtle rhythmic signs are the foundation of "semiology", the modern study of chant nuance.
From 1833 the monks of Solesmes photographed and collated hundreds of manuscripts, producing the Graduale and Liber Usualis.
Pope Pius X's motu proprio declared Gregorian chant the Church's own music and the Solesmes editions its standard.
Semiology, led by Dom Eugène Cardine, reads the earliest neumes to restore the flexible, word-born rhythm the square notation had flattened.
Different ensembles interpret chant's rhythm very differently — from the even flow of Solesmes to the ornate, near-Byzantine readings of Ensemble Organum.
Nearly everything in Western music grows from this single unadorned line. The staff and solfège we still teach are Guido's. Polyphony began as chant with a second voice added. For six hundred years composers built their Masses and motets on chant melodies laid down as a cantus firmus. To study chant is to stand at the source of the river.
The five-line staff, clefs, note-names and sight-singing all descend directly from Guido's chant lines.
Organum, the motet, the cantus-firmus Mass, and thus the entire Renaissance, begin as chant with voices added above and below.
The eight modes shaped Western melody for a millennium and still colour folk song, jazz and film music today.
"Let the singing be done not lightly nor frothily, but with gravity and reverence... let us so sing that our mind may be in harmony with our voice."
— attributed to St Bernard of Clairvaux, on the singing of the Officec. 600 – present · The chant has never fallen silent.