What is a medieval secular composition with original melodies that accompanied a preexisting tenor line called

motet

madrigal

Chanson de Geste

plainchant

motet

Explanation:

The motet is a non-liturgical composition that began in the Middle Ages, in the thirteenth century, and continued to be a source of compositions, and this piece is named after the French MOT which means WORD. This composition is one of the most important forms of polyphonic music that emerged around 1200.

chanson de geste

Explanation:

that sounds more like midieval time thing