It is generally accepted nowadays that the earliest tropes originated sometime during the 9th century. The documentary evidence, meagre though it is, seems fairly definite on this point. And although few, if any, of the earliest surviving manuscripts were copied much before the beginning of the 10th century, it is reasonable to suppose that at least some of the dozens of pieces found in them were composed somewhat earlier. A number of models have been suggested for the earliest tropes. Certain of their characteristics have parallels in the Byzantine and other rites, above all in the addition of newly composed introductory material to chants already in existence. Many tropes also have texts derived from the various Latin translations of the Bible or from hymns and antiphons. Yet whatever their origins even the earliest pieces exhibit ingenious and imaginative structural features. A slow and gradual evolution from simpler to more complex forms might just succeed in accounting for the origin of the trope; but this later variety and subtlety would be unexplained. These matters are easily disregarded. The creation of chant is too often reduced to a mechanical process serving the requirements of liturgy. But tropes are interesting in themselves, and there is ample evidence to suggest that they were regarded as such during the Middle Ages.