trope

trope, in medieval church music, melody, explicatory text, or both added to a plainchant melody. Tropes are of two general types: those adding a new text to a melisma (section of music having one syllable extended over many notes); and those inserting new music, usually with words, between existing sections of melody and text. Troping was rooted in similar practices in the ancient Byzantine liturgy and arose in the West, probably in France, by the...