1.A plainsong melody serving as the basis of a polyphonic composition by the addition of contrapuntal voices, as in 5th-century polyphony.
固定旋律，固定曲调：与对位声部一起作为一首复调音乐基础的一段素歌旋律，如在5世纪复调音乐中。
2.A plainsong melody serving as the basis of a polyphonic composition by the addition of contrapuntal voices, as in 5th-century polyphony.