Gregorian chant is the main type of Western plainchant, a style of sacred music with only one melody line and no instrumental accompaniment. It is sung in Latin (and sometimes Greek) by the Roman Catholic Church. This music developed mostly in western and central Europe during the 9th and 10th centuries, with later changes and additions. While some people believe Pope Gregory I created Gregorian chant, scholars think he only ordered the collection of melodies from across the Christian world. These melodies were later combined and refined by musicians during the Carolingian period, blending elements of Old Roman chant and Gallican chant.
Gregorian chants were first grouped into four, then eight, and finally twelve modes. Common musical features include a specific range of pitches, patterns of intervals based on a central note (called the final), and repeated sections called incipits and cadences. Melodies often revolve around a specific note (the reciting tone) and use short musical phrases combined through a process called centonization to form related chants. The scale patterns are built from connected and disconnected groups of four notes (tetrachords), creating a larger system of pitches called the gamut. These chants can be sung using six-note patterns called hexachords. Gregorian melodies are written using neumes, an early form of musical notation that led to the modern four- or five-line staff. Later, multi-voice versions of Gregorian chant, called organum, became an early step in the development of Western polyphony.
Traditionally, Gregorian chant was performed by male and female choirs in churches or by religious groups in their chapels. It is the music used in the Roman Rite during Mass and monastic prayer services. Although Gregorian chant replaced other plainchant traditions in the Christian West and became the official music of the Church, some traditions like the Ambrosian chant in Milan and the Mozarabic chant in Spain continue to be used. While Gregorian chant is no longer required, the Roman Catholic Church still considers it the most appropriate music for worship.
History
Singing has been part of Christian worship since the beginning of the Church. Many scholars believe that Jewish worship practices, especially the singing of psalms, greatly influenced early Christian rituals. Like the Jewish people before them, early Christians read Scripture and sang chants. Although new Christian liturgical practices were created, many of these traditions came from Jewish psalm singing. The earliest Christian chants were passed down by Jews who sang them. Early Christian ceremonies also included Jewish worship elements that later appeared in chant traditions. Prayer times called "canonical hours" originated from Jewish prayer schedules. Words like "Amen," "Alleluia," and "Hosanna" come from Hebrew, and the three-part "Sanctus" in Christian chants is based on the three-part "Kadosh" in Jewish rituals.
The New Testament mentions singing hymns during the Last Supper: "When they had sung the hymn, they went out to the Mount of Olives" (Matthew 26:30). Other early Christian writers, such as Pope Clement I, Tertullian, St. Athanasius, and Egeria, also described singing in Christian worship, though their writings do not clearly explain how the music sounded.
Musical elements used later in the Roman Rite began appearing in the 3rd century. A text called The Apostolic Tradition, written by Hippolytus, mentions Jewish psalms being sung with "Alleluia" as a repeated line during early Christian feasts. Chants used in daily prayer times, called the Office, began in the early 4th century when monks in the desert, following St. Anthony, started singing all 150 psalms every week. By 375, a style of singing called antiphonal psalmody became popular in the Christian East. In 386, St. Ambrose introduced this style to the West. In the 5th century, a music school called the Schola Cantorum was created in Rome to train church musicians.
Scholars still debate how plainchant developed between the 5th and 9th centuries because few records from this time exist. Around 410, St. Augustine described a type of singing called responsorial during Mass. In 520, Benedict of Nursia created a rule for monastic life that included instructions for daily prayer chants. Around 678, Roman chant was taught in York, England. During this time, different regions in the West developed their own plainchant traditions, such as Celtic chant in the British Isles, Mozarabic chant in Spain, Gallican chant in Gaul, and Ambrosian chant in Italy. These traditions may have come from a shared collection of plainchant songs used in the 5th century, after the fall of the Western Roman Empire.
John the Deacon, who wrote about Pope Gregory I around 872, said the pope collected chants from different traditions to create a unified set of songs for the Church. Gregory reorganized the Schola Cantorum and made church services more consistent by gathering chants from various regions. He kept some songs, changed others, and assigned specific chants to different parts of worship. According to Donald Jay Grout, Gregory’s goal was to bring together chants from different traditions into a single, organized system for the entire Western Church. His love for music was noted only 34 years after his death, and people began praising him as the best music-loving pope. Although later stories exaggerated his achievements, his work helped make his name associated with Gregorian chant.
The Gregorian chant collection was later organized for use in the Roman Rite. Scholars discuss how Roman and Carolingian (Frankish) traditions influenced the development of plainchant. In the late 8th century, Carolingian kings gained more power over the popes. Pope Stephen II used Roman chant during a Mass in Gaul in 752–753. Charlemagne’s father, Pepin, replaced local Gallican rituals with Roman ones to strengthen ties with Rome. In 785–786, Pope Adrian I sent a book of Roman chants to Charlemagne’s court. James McKinnon notes that a project led by Chrodegang of Metz in the 8th century compiled the core Roman Mass liturgy and promoted its use in France and Gaul.
Scholars like Willi Apel and Robert Snow agree that Gregorian chant developed around 750 by combining Roman and Gallican chants, with support from Carolingian rulers. Andreas Pfisterer and Peter Jeffery show that older Roman melodies are clearly present in the final Gregorian chant collection. Other changes included adapting chants to local styles and fitting them into a system of eight musical modes based on ancient Greek traditions. The Metz project also created a new way to write music using symbols called neumes. This system evolved into the staff lines used in modern plainchant notation, introduced by Guido d’Arezzo in the 11th century. The Frankish-Roman Carolingian chant collection, expanded to cover the entire liturgical year, became known as "Gregorian."
The changes in the new chant system were so significant that some scholars think the name "Gregorian" might honor Pope Gregory II, who lived around the same time. However, stories about Pope Gregory I, who lived earlier, led people to believe he created Gregorian chant. He was often shown receiving music from a dove symbolizing the Holy Spirit, suggesting divine inspiration. Scholars agree that the melodies in Gregorian chant did not exist in their current form during Gregory I’s time. Also, the system for writing plainchant with neumes was not developed until after his death. Despite this, some people still believe Gregory I wrote Gregorian chant.
Gregorian chant spread quickly across Europe in a uniform way. Charlemagne, after becoming Holy Roman Emperor, promoted Gregorian chant throughout his empire to strengthen religious and political control. From England and Germany, it spread to Scandinavia, Iceland, and Finland. In 885, Pope Stephen V banned Slavonic liturgy, making Gregorian chant the main form of worship in Eastern Catholic regions like Poland, Moravia, and Slovakia.
Other plainchant traditions in the Christian West faced competition from Gregorian chant. Charlemagne continued his father’s policy of favoring the Roman Rite over local Gallican traditions. By the 9th century, the Gallican Rite and chant were mostly replaced, though some resisted. The Gregorian chant of the Sarum Rite replaced Celtic chant. Gregorian chant coexisted with Beneventan chant for over a
Musical form
Gregorian chant is a type of vocal music. The words in the chant can be sung in different ways. The simplest way is to sing each syllable on the same note, called "syllabic." Many chants are mostly syllabic, with only a few syllables having more than one note. "Neumatic" chants have more notes grouped together, written as a single symbol. "Melismatic" chants are the most complex, with long melodies sung on single vowels, such as in the Alleluia, where one syllable can have many notes.
Gregorian chants are divided into two main types: recitatives and free melodies. Recitatives are the simplest, using mostly one note called the "reciting tone." Other notes appear in parts like the beginning, middle, or end of the chant. These chants are mostly syllabic. For example, a chant with 127 syllables might use one note most of the time. Recitatives are often used in parts of the Mass, like the Collect, Epistle, and Gospel.
Psalmodic chants include both recitatives and free melodies. They involve singing psalms and can be sung in different ways, such as directly, with alternating groups, or with a call-and-response style. In direct psalmody, verses are sung without repeats. Many psalmodic chants are antiphonal, where two groups alternate singing. Originally, antiphonal chants had two choirs singing verses and a repeated line called an antiphon. Over time, these chants became simpler. Antiphonal chants still show their origins through the use of reciting tones. Chants like the Kyrie and Gloria are not antiphonal but may be performed in an antiphonal style.
Responsorial chants, like the Gradual and Alleluia, have a repeated line called a respond, sung by a choir, alternating with verses sung by a soloist. These chants often combine different musical phrases in a method called "centonization." Tracts are melismatic chants with repeated musical patterns.
Gregorian chant was used for different purposes in the Roman Catholic Church. Recitatives were used for texts spoken by priests or deacons. Antiphonal chants accompanied actions like entering the church or distributing the Eucharist. Responsorial chants helped explain readings.
Non-psalmodic chants, such as hymns and sequences, were meant for the whole congregation to sing. Hymns use the same melody for each stanza, while sequences repeat the same melody in each pair of lines.
Early plainchant, like much Western music, used the diatonic scale. Modal theory, which came later, combined ideas from ancient Greece and practical music traditions. Early writings, like the Enchiriadis treatises, described a system of notes based on D, E, F, and G. This system had unusual notes not used later. Hucbald later described a diatonic scale with a flexible B-flat.
Around 1025, Guido d'Arezzo created the "gamut," a system of notes grouped into six-note sets called hexachords. These could be based on C, F, or G, with B-flat as a regular note. Notes outside these groups were called "musica ficta."
Gregorian chant was divided into eight modes, inspired by Byzantine music. Each mode has a final note, a secondary note, and a range of pitches. If the final note is near the middle of the range, the mode is called "plagal." If the final note is lower and the range is wide, it is called "authentic." Modes are named with Greek prefixes, like "hypo-" for plagal. In Latin manuscripts, they are labeled as Protus, Deuterus, etc.
Some chants, like those ending on A, B, or C, are sometimes called Aeolian, Locrian, or Ionian, but these are treated as variations of other modes. The pitch of Gregorian chant is not fixed, so it can be sung in different ranges.
Some chants use a style called "chromaticism," where notes between E and F are used, outside the hexachord system. This shows that not all chants fit neatly into the eight modes or hexachord system.
Performance
Gregorian chant was originally used for singing the Office by male and female religious people and for singing parts of the Mass related to the lay faithful (both male and female), the celebrant (a priest, always male), and the choir (made up of male ordained clergy, except in convents). In areas outside larger cities, the number of available clergy decreased, so lay men began singing these parts. The choir was considered an official liturgical duty reserved for clergy, so women were not allowed to sing in the Schola Cantorum or other choirs except in convents, where women could sing the Office and parts of the Mass related to the choir as part of their consecrated life.
Chant was typically sung in unison. Later changes included tropes, which are new texts sung to the same melodic phrases in a melismatic chant (for example, repeating an entire Alleluia melody on a new text or repeating a full phrase with a new text that comments on the previously sung text), and various forms of organum, which are improvised harmonic embellishments of chant melodies focusing on octaves, fifths, fourths, and later, thirds. Tropes and organum are not part of the chant repertory itself. The main exception is the sequence, which originated from adding new texts to the extended melisma of Alleluia chants known as the jubilus. However, sequences, like tropes, were later officially banned. The Council of Trent removed sequences from the Gregorian corpus, except for those used on Easter, Pentecost, Corpus Christi, and All Souls' Day.
Little is known about the specific vocal styles or performance practices used for Gregorian chant in the Middle Ages. At times, clergy were encouraged to perform with more restraint and piety, suggesting that highly skilled performances did occur, contrary to the modern idea of Gregorian chant as slow, mood-based music. This tension between musical skill and religious devotion dates back to early times, as Gregory the Great himself criticized the practice of promoting clerics based on their singing ability rather than their preaching. However, Odo of Cluny, a famous monastic reformer, praised the intellectual and musical skill found in chant:
True antiphonal performance by two alternating choruses still happens in some German monasteries. However, antiphonal chants are generally performed in responsorial style, with a solo cantor alternating with a chorus. This practice began in the Middle Ages. Another medieval change involved the solo cantor singing the opening words of responsorial chants, with the full chorus finishing the end of the opening phrase. This allowed the soloist to set the pitch for the chorus and signal the choral entrance.
Because Gregorian chant was traditionally taught orally, modern attempts to recreate its intended rhythm from written notation have always been debated by scholars. This is complicated by the use of ornamental neumes in early manuscripts, which make rhythm interpretation difficult. Some neumes, like the pressus, pes quassus, and strophic neumes, may indicate repeated notes or lengthened notes with added ornaments. By the 13th century, with the use of square notation, most chant was sung with approximately equal note durations, although Jerome of Moravia noted exceptions where certain notes, such as the final notes of a chant, were lengthened.
While the standard repertory of Gregorian chant was gradually replaced by new forms of polyphony, the earlier melodic and rhythmic refinements of monophonic chant fell out of use. Later versions, such as the Editio medicaea of 1614, rewrote chant so that melismata (melodies with melodic emphasis) fell on accented syllables. This aesthetic remained until the late 19th century, when scholars like Peter Wagner, Pothier, and Mocquereau re-examined chant. These scholars divided into two groups.
One group, including Wagner, Jammers, and Lipphardt, supported adding rhythmic meters to chants, though they disagreed on the method. Another group, led by Pothier and Mocquereau, supported a free rhythm with equal note values, though some notes were lengthened for emphasis or musical effect. Modern Solesmes editions of Gregorian chant follow this approach. Mocquereau divided melodies into two- and three-note phrases, each starting with an ictus (a beat-like mark in chantbooks). These units combined into larger phrases through a system of hand gestures. This method was widely used in the 20th century, promoted by Justine Ward’s music education programs for children, until the liturgical reforms of Pope Paul VI reduced the role of chant and new research questioned Mocquereau’s rhythmic theories.
Today, most performances of Gregorian chant avoid regular beats or metric accents, mainly for aesthetic reasons. The text determines the accent, while the melody determines the phrasing. The note lengthenings suggested by the Solesmes school remain influential, though they are not strictly required.
Dom Eugène Cardine (1905–1988), a monk from Solesmes, published his "Semiologie Gregorienne" in 1970, explaining the musical meaning of the neumes in early chant manuscripts. Cardine showed the variety of neumes and their graphic variations, which cannot be fully expressed in square notation. This diversity in notation likely had a practical and musical purpose. Nine years later, the Graduale Triplex was published, combining the Roman Gradual (which includes all Mass chants for a year) with the neumes from two important manuscripts (Sankt Gallen and Laon) copied over a 4-line staff. The Graduale Triplex made the original notation from these manuscripts widely accessible in a single book and was a major advancement. Cardine’s students continued his work, some applying his findings to performance practice.
Studies by Cardine and his students (such as Godehard Joppich, Luigi Augustoni, Johannes B. Göschl, Marie-Noël Colette, Rupert Fischer, Marie-Claire Billecocq, and Alexander M. Schweitzer) have shown that rhythm in 10th-century Gregorian chant manuscripts (like those from Sankt Gallen and Laon) displays significant rhythmic diversity and melodic-rhythmic ornamentation, which has no living performance tradition in the Western world. Groups that aim to sing according to manuscript traditions began forming after 1975. Some researchers now look to non-Western liturgical traditions, where modal monophony was never abandoned.
Another group, the mensuralists or proportionalists, believes rhythm should be interpreted proportionally, with short notes exactly half the length of long notes. This view is supported by historical figures like St. Augustine, Remigius, Guido, and Aribo. John Blackley and his "Schola Ant
Liturgical functions
Gregorian chant is sung during the Office, which takes place at specific times of the day, and during the Mass. Texts called accentus are sung by bishops, priests, and deacons, usually in a single, simple tone with basic musical patterns at certain points in each sentence. More complex chants are performed by trained solo singers and choirs. The Graduale Romanum includes the proper chants of the Mass, such as the Introit, Gradual, Alleluia, Tract, Offertory, and Communion, as well as the complete Kyriale, which contains settings of the Mass Ordinary. The Liber usualis includes the chants from the Graduale Romanum and the most commonly used Office chants.
The Introit, Gradual, Alleluia, Tract, Sequence, Offertory, and Communion chants are part of the Proper of the Mass. In Latin, "Proprium Missae" refers to the chants of the Mass that have unique texts for each Sunday throughout the year, unlike the "Ordinarium Missae," which have fixed texts but different melodies (Kyrie, Gloria, Sanctus, Benedictus, Agnus Dei).
Introits are used during the procession of the officiants. They are antiphonal chants, usually made up of an antiphon, a verse from a psalm, a repetition of the antiphon, a doxology (Gloria Patri), and a final repetition of the antiphon. The melodies of Introits often follow specific tonal patterns.
Graduals are chants that follow the reading of the Epistle. They are created by combining short musical phrases, like pieces of a puzzle, to form the full melody. Graduals include an elaborate verse, making them consist of two parts, A and B. Sometimes, the first part is repeated, forming a structure called A B A. These chants are often sung by a solo cantor and feature intricate, flowing musical notes.
The Alleluia is known for its jubilus, a long, joyful musical note on the last vowel of "Alleluia." It has two parts: the alleluia itself and a psalm verse that identifies it (e.g., "Alleluia V. Pascha nostrum"). The final note of the verse matches the jubilus of the Alleluia. Alleluias are not sung during penitential times like Lent. Instead, a Tract is chanted, usually using texts from the Psalms.
Sequences are poems set to music, often based on couplets. While many sequences are not part of the official Gregorian repertory, some well-known ones include "Victimae paschali laudes" and "Veni Sancte Spiritus." According to Notker Balbulus, an early composer of sequences, they originated from adding words to the long musical notes of the jubilus in Alleluia chants.
The Kyrie, Gloria, Credo, Sanctus, Benedictus, and Agnus Dei use the same text in every Mass service. These chants are called "Ordinary" because they follow the regular order of the Mass. The Kyrie repeats "Kyrie eleison" ("Lord, have mercy") and "Christe eleison" ("Christ have mercy") three times each. Older versions may include "Kyrie eleison imas" ("Lord, have mercy on us"). The Kyrie uses Greek instead of Latin and features repeated musical patterns. For example, the Kyrie ad. lib. VI from a Cambrai manuscript follows a structure like ABA CDC EFE', with changes in pitch between sections. The final section, E', has its own pattern (aa'b), creating a sense of climax.
The Gloria includes the Greater Doxology, and the Credo includes the Nicene Creed. Because these texts are long, the chants often break into smaller musical sections that match the text. The Credo was the last Ordinary chant added to the Mass, so there are fewer Credo melodies in the Gregorian collection.
Like the Kyrie, the Sanctus and Agnus Dei also include repeated texts, which their musical structures often use.
Technically, the "Ite missa est" and "Benedicamus Domino," which end the Mass, belong to the Ordinary. They have their own Gregorian melodies, but because they are short and simple, and rarely used in later compositions, they are often left out of discussions.
Gregorian chant is sung during the canonical hours of the monastic Office, especially in antiphons used to sing the Psalms, in the Great Responsories of Matins, and in the Short Responsories of the Lesser Hours and Compline. Psalm antiphons in the Office are usually short and simple, unlike the more complex Great Responsories.
At the end of the Office, one of four Marian antiphons is sung. These songs—Alma Redemptoris Mater, Ave Regina caelorum, Regina caeli laetare, and Salve, Regina—are from the 11th century and have more complex music than most Office antiphons. Willi Apel described these songs as "among the most beautiful creations of the late Middle Ages."
Influence
Gregorian chant had a big influence on the development of medieval and Renaissance music. Modern staff notation came from Gregorian neumes. The square notation used for plainchant was borrowed and changed to fit other types of music. Some groups of neumes showed repeating rhythms called rhythmic modes. Rounded noteheads became more common than older square and lozenge shapes in the 15th and 16th centuries, though chantbooks still used square notation. By the 16th century, the fifth line added to the musical staff became standard. The bass clef and the flat, natural, and sharp accidentals came directly from Gregorian notation.
Gregorian melodies provided musical material and were used as models for tropes and liturgical dramas. Vernacular hymns like "Christ ist erstanden" and "Nun bitten wir den Heiligen Geist" used original Gregorian melodies with translated texts. Secular tunes such as the popular Renaissance "In Nomine" were based on Gregorian melodies. Starting with improvised harmonizations of Gregorian chant called organum, Gregorian chants became important in medieval and Renaissance polyphony. Often, a Gregorian chant (sometimes changed slightly) was used as a cantus firmus, so the notes of the chant guided the harmonic progression. The Marian antiphons, especially "Alma Redemptoris Mater," were often arranged by Renaissance composers. Using chant as a cantus firmus was common until the Baroque period, when stronger harmonic progressions with an independent bass line became standard.
The Catholic Church later allowed polyphonic arrangements to replace Gregorian chant in the Ordinary of the Mass. This is why the Mass, as written by composers like Palestrina or Mozart, includes a Kyrie but not an Introit. The Propers may also be replaced by choral settings on special occasions. Composers like William Byrd and Tomás Luis de Victoria often wrote polyphonic versions of the Propers. These arrangements usually included parts of the original chant.