What the tradition attributes to Yared is nothing less than its whole apparatus of sacred song: zema, the chant itself, its three modes, the great cycle of chant books led by the Deggua, the hymnary for the year's feasts and fasts, and the melekket, the notation of letters and signs written above the text that cues melody, one of the oldest indigenous musical notations in Christendom, though surviving manuscripts with notation date from centuries after his era. Around the chant stands a performance practice the tradition also traces to him: the debtera, the trained cantors, with their prayer staffs, sistra and drums, and the grave liturgical dance, the shibsheba, that accompanies the great feasts.
Scholars of Ethiopian music read this inheritance historically: the corpus grew and was systematized across centuries, notation appears in manuscripts from the medieval period onward, and assigning the whole to one Aksumite composer is the tradition's way of naming its own foundation. That is how the atlas records it, a traditional attribution carried by an unbroken living practice rather than a documented sixth century authorship. The practice itself is the point: zema is sung today in Ethiopian and Eritrean churches on the same modes the tradition received, school lineages of debtera still transmit the Deggua by apprenticeship, and Yared's feast is kept with the chant he is honored as father of.