Conductus style
An earlier medieval part-writing style (organum/conductus) in which all voices declaim the same text syllabically together.
What it means
Conductus style refers to a polyphonic texture in which all voices sing the same text at the same time, syllable for syllable, so that the voices move together like a homogeneous, chordal block on the page. The name derives from the conductus, the genre in which this style prevailed.
Musical use
The conductus was a major genre of sacred and secular Latin poetry in the 12th and early 13th centuries, set to a freely composed melody rather than a pre-existing chant. In conductus style, all voices move in the same rhythm, keeping the text intelligible simultaneously in every voice — unlike the contemporary organum style, where a long-held tenor drawn from chant is decorated by faster, melismatic upper voices. This contrast with organum, where the voices move rhythmically independent of one another, is the central stylistic distinction of the Notre Dame school.
Performance practice
When listening to medieval polyphony, watch how the voices relate rhythmically: if they move together, syllable by syllable, you are hearing conductus style; if one voice holds long notes beneath faster ones, it is closer to organum.