A medieval Latin term denoting two musical forms. The term is known only from Johannes de Grocheio’s treatise De musica (c1300), where it is discussed along with the stantipes (see Estampie). Grocheio made a distinction between a vocal and an instrumental form, calling the former cantilena ductia and the latter merely ductia. The discussion of the vocal form is far from clear: Grocheio stated that ‘the ductia is a song [cantilena], light and rapid in ascent and descent, which is sung by boys and girls for dances [in choreis a iuvenibus et puellis] like the French song Chi encor querez amoretes’ (Rohloff, p.132); that song has not survived. Grocheio’s subsequent discussion and his comparisons with other songs do not clarify this description of the form.
The discussion of the instrumental form is much clearer. It is a textless composition ‘measured with an appropriate beat [cum decenti percussione mensuratus]’, implying that ‘beats [ictus] measure it and the motions of the one who does it; they spur the human mind to move ornately [ornate] according to the art which is called dancing [ballare]; and they measure its motion in ductias and dances [choreis]’ (Rohloff, p.136). The stantipes and the ductia, according to Grocheio, consist of a certain number of puncta (see Punctum), each of which in turn consists of two parts identical with one another in the beginning but with different endings called apertum (‘open’) and clausum (‘closed’). The stantipes is supposed to have six or seven puncta, the ductia only three or four. Levarie (JAMS, xxvii, 1974, p.367) has suggested that, beside this distinction, it is the ductia’s constant (decenti: ‘regular’) number of beats per punctus that differentiates it from the estampie, whose puncta have a varying number of beats. Grocheio’s ductia would then resemble the pieces entitled ‘dansse’ (see Dansse real) in the ‘Manuscrit du Roi’ (F-Pn fr.844, ff.5r, 104v), which each have three regular puncta.
E. Rohloff: Die Quellenhandschriften zum Musiktraktat des Johannes de Grocheio (Leipzig, 1972)
T.J. McGee: ‘Medieval Dances: Matching the Repertory with Grocheio's Descriptions’, JM, vii (1989), 498–517
HENDRIK VAN DER WERF