Medieval music refers to 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. Medieval music can be divided into Early (500–1150), 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, while other music used only instruments or both voices and instruments (typically with the instruments accompanying the voices) . Medieval music was created for a number of different uses and contexts, resulting in different music genres. Liturgical as well as more general sacred contexts were important, but secular types emerged as well, including love songs and dances.

The medieval period saw the creation and adaptation of systems of music notation which enabled creators to document and transmit musical ideas more easily, although notation coexisted with and complemented oral tradition. The vast majority of medieval music was monophonic, meaning there was only a single melody line. The development of polyphonic music (more than one melody line played at the same time) was a major shift towards the end of the era that laid the foundations for Renaissance styles of music. Gregorian chant, consisting of a single line of vocal melody, unaccompanied in free rhythm, was one of the most common forms of medieval music.

Ars Nova was a new style of music originating in France and Italy in the 14th century. The late medieval period (14th century onwards) saw the flourishing of Ars Nova, a sophisticated form of polyphony that used complex rhythms and harmonies.

In summary, medieval music is a broad term that encompasses the sacred and secular music of Western Europe during the Middle Ages, from approximately the 6th to 15th centuries. It includes liturgical music used for the church, other sacred music, and secular or non-religious music. The vast majority of medieval music was monophonic, but the development of polyphonic music was a major shift towards the end of the era that laid the foundations for Renaissance styles of music. Ars Nova was a new style of music originating in France and Italy in the 14th century.