Ligature (music)

In medieval music notation, a ligature is a graphic symbol that represents two or more notes that are written and sung in a single gesture, and on a single syllable. The actual notation and meaning of ligatures has changed significantly throughout the history of western music.

The early notation of Gregorian chant used ligatures predominantly, with few single notes. This usage is a consequence of the purpose of the earliest chant notations, namely as a mnemonic for the shapes of musical gestures. In later polyphonic music, such as that of the Notre Dame school, ligatures were used to indicate the rhythmic mode of a work. This system of notational ligatures was first codified by Johannes de Garlandia in the 13th century.

Over the next few hundred years, the system of neumes with ligatures was expanded greatly to include a number of different patterns of rhythms and melismas.

In the 16th and 17th centuries, the use of ligatures became increasingly rare. Their presence was usually just an artifact of printing tradition rather than having any explicit meaning.

In transcribing to modern notation, where no compound graphs as ligatures exist, editors usually indicate by a hook or (less often in polyphonic music) a slur those notes that were combined into a ligature.