 While based on a cantus firmus, it is also a paraphrase mass, for fragments of the tune appear in all voices.Technically it is almost restrained, compared to the other "L'homme armé" mass, until the closing Agnus Dei, which contains a complex canonic structure including a rare retrograde canon, around which other voices are woven.The paraphrase technique differs from the cantus-firmus technique in that the source material, though it still consists of a monophonic original, is embellished, often with ornaments.