Gregorian chant in the context of "Organum"

A chant (from French chanter, from Latin cantare, "to sing") is the iterative speaking or singing of words or sounds, often primarily on one or two main pitches called reciting tones. Chants may range from a simple melody involving a limited set of notes to highly complex musical structures, often including a great deal of repetition of musical subphrases, such as Great Responsories and Offertories of Gregorian chant. Chant may be considered speech, music, or a heightened or stylized form of speech. In the Late Middle Ages, some religious chant evolved into song (forming one of the roots of later Western music).

In chant, a reciting tone (also called a recitation tone) can refer to either a repeated musical pitch or to the entire melodic formula for which that pitch is a structural note. In Gregorian chant, the first is also called tenor, dominant or tuba, while the second includes psalm tones (each with its own associated Gregorian mode) as well as simpler formulae for other readings and for prayers.

Classical music generally refers to the art music of the Western world, considered to be distinct from Western folk music or popular music traditions. It is sometimes distinguished as Western classical music, as the term "classical music" can also be applied to non-Western art musics. Classical music is often characterized by formality and complexity in its musical form and harmonic organization, particularly with the use of polyphony. Since at least the ninth century, it has been primarily a written tradition, spawning a sophisticated notational system, as well as accompanying literature in analytical, critical, historiographical, musicological and philosophical practices.

Rooted in the patronage of churches and royal courts in Europe, surviving early medieval music is chiefly religious, monophonic and vocal, with the music of ancient Greece and Rome influencing its thought and theory. The earliest extant music manuscripts date from the Carolingian Empire (800–887), around the time which Western plainchant gradually unified into what is termed Gregorian chant. Musical centers existed at the Abbey of Saint Gall, the Abbey of Saint Martial and Saint Emmeram's Abbey, while the 11th century saw the development of staff notation and increasing output from medieval music theorists. By the mid-12th century, France became the major European musical center: the religious Notre-Dame school first fully explored organized rhythms and polyphony, while secular music flourished with the troubadour and trouvère traditions led by poet-musician nobles. This culminated in the court-sponsored French ars nova and Italian Trecento, which evolved into ars subtilior, a stylistic movement of extreme rhythmic diversity. Beginning in the early 15th century, Renaissance composers of the influential Franco-Flemish School built on the harmonic principles in the English contenance angloise, bringing choral music to new standards, particularly the mass and motet. Northern Italy soon emerged as the central musical region, where the Roman School engaged in highly sophisticated methods of polyphony in genres such as the madrigal, which inspired the brief English Madrigal School.

In music, monophony is the simplest of musical textures, consisting of a melody (or "tune"), typically sung by a single singer or played by a single instrument player (e.g., a flute player) without accompanying harmony or chords. Many folk songs and traditional songs are monophonic. A melody is also considered to be monophonic if a group of singers (e.g., a choir) sings the same melody together at the unison (exactly the same pitch) or with the same melody notes duplicated at the octave (such as when men and women sing together). If an entire melody is played by two or more instruments or sung by a choir with a fixed interval, such as a perfect fifth, it is also said to be monophony (or "monophonic"). The musical texture of a song or musical piece is determined by assessing whether varying components are used, such as an accompaniment part or polyphonic melody lines (two or more independent lines).

In the Early Middle Ages, the earliest Christian songs, called plainchant (a well-known example is Gregorian chant), were monophonic. Even into the twenty-first century, songwriters still often write songs that intersperse sections using monophony, heterophony (two singers or instrumentalists doing varied versions of the same melody together), polyphony (two or more singers or instrumentalists playing independent melodic lines at the same time), homophony (a melody accompanied by chords), or monody (a single melodic line with instrumental accompaniment) elements throughout the melody to create different atmospheres and styles. Monophony may not have underlying rhythmic textures, and must consist of only a single melodic line.

Medieval music encompasses the sacred and secular music of Western Europe during the Middle Ages, from approximately the 6th to 15th centuries. It is the first and longest major era of Western classical music and is followed by the Renaissance music; the two eras comprise what musicologists generally term as early music, preceding the common practice period. Following the traditional division of the Middle Ages, medieval music can be divided into Early (500–1000), High (1000–1300), and Late (1300–1400) medieval music.

Medieval music includes liturgical music used for the church, other sacred music, and secular or non-religious music. Much medieval music is purely vocal music, such as Gregorian chant. Other music used only instruments or both voices and instruments (typically with the instruments accompanying the voices).

Metz (/mɛts/ METS; French: [mɛs] ; Latin: Divodurum Mediomatricorum, then Mettis) is a city in northeast France located at the confluence of the Moselle and the Seille rivers. Metz is the prefecture of the Moselle department and the seat of the parliament of the Grand Est region. Located near the tripoint along the junction of France, Germany and Luxembourg, the city forms a central part of the European Greater Region and the SaarLorLux euroregion.

Metz has a rich 3,000-year history, having variously been a Celtic oppidum, an important Gallo-Roman city, the Merovingian capital of Austrasia, the birthplace of the Carolingian dynasty, a cradle of the Gregorian chant, and one of the oldest republics in Europe. The city has been steeped in French culture, but has been strongly influenced by German culture due to its location and history.

A Gregorian mode (or church mode) is one of the eight systems of pitch organization used in Gregorian chant.