torculus

The torculus is a medieval musical ligature used in early polyphony to indicate a specific three-note melodic figure. The term derives from Latin and is associated with an arch-like contour in the melodic line, reflecting the characteristic shape of the notes within the ligature.

In practice the torculus is realized as a three-note sequence whose shape resembles an arch: the line rises by step to a peak and then moves by step in the opposite direction. The exact pitches and direction can vary with local practice and notation systems, but the archetypal torculus is distinguished by its distinctive three-note contour within a single ligature.

The torculus appears in late medieval notation, particularly in references from the Ars Nova period in France and Italy, and it occurs in both chant-derived discant lines and more elaborate polyphonic settings. It is one of several named ligatures in mensural notation, alongside figures such as clivis, porrectus, and scandicus, which were used to signal melodic motion within a notational system that sometimes treated ligatures as more than mere rhythm.

Modern scholarship treats the torculus as a category of melodic gesture rather than a single fixed formula, with editors and researchers sometimes differing in reconstructing exact pitches depending on the manuscript source. It remains a topic in studies of medieval rhythmic notation and polyphonic practice, illustrating how early theorists encoded contour and motion in written music.