The trope repertory fell by two orders of magnitude

Claim (verbatim)

Tropes - the interpolated additions that wrapped, prefaced, and glossed the fixed chants of the mass - were among the most productive genres of the central Middle Ages, and the Corpus Troporum has inventoried them exhaustively: thousands of distinct trope elements for the Introit alone, thousands more for the Gloria, Sanctus, Agnus, and the rest, copied across hundreds of tenth- to twelfth-century sources. Then they were purged. The thirteenth-century reforms and the standardizing plenary missals stripped tropes out, and the Tridentine Missal of 1570 contains none. The mechanism is deliberate liturgical retrenchment: the trope was optional festal ornament, the first thing cut when uniformity became the value, so a genre that had numbered in the thousands per category was reduced, for the Proper tropes, to nothing that survived into the printed liturgy. This is contraction by an order of magnitude and more - a whole compositional economy erased not by accident of survival but by editorial policy. Prediction restated: the count of distinct Introit-trope elements inventoried in the Corpus Troporum exceeds the count surviving in any post-1570 printed missal by more than a hundred to one, the Proper tropes effectively going to zero.

Prediction clause (verbatim)

Prediction: the number of distinct Introit-trope elements inventoried in the Corpus Troporum exceeds the number of Introit tropes present in any post-1570 printed Roman missal by more than 100 to 1, with the printed-missal count effectively zero for Proper tropes (primary clause: the greater-than-100:1 medieval-to-post-Trent Introit-trope ratio; the verdict follows it). A trope element is counted as a distinct catalogued unit in the Corpus Troporum; coverage guard: the medieval inventory is itself a survival floor because lost tropers depress it, so the true contraction is larger, and the test voids only if the Corpus Troporum Introit volumes inventory fewer than 500 elements.

Kill-dataset (verbatim)

Kill: the Corpus Troporum published inventories of Introit tropes as the medieval count, against the trope content of the post-1570 Tridentine printed missal as the survival count; the operation is a contraction ratio between the catalogued medieval repertory and the post-Trent printed liturgy.

Novelty / leakage triage

already answered in the literature

Both sides of the ratio are published: the Corpus Troporum volumes inventory the proper trope repertory in the thousands of catalogued elements - the Christmas- and Easter-cycle volumes alone put the count far past the 500-element void threshold - and the total absence of tropes from the 1570 Missale Romanum is a stated commonplace of the survey literature, checkable against the Sodi-Triacca editio princeps facsimile. A greater-than-100:1 contraction against an effectively zero post-Trent survivor count is guaranteed by facts already in print, not an open computation; this is the post-Trent collapse leak-alert in its trope form.

• R. Jonsson (ed.), Corpus Troporum I: Tropes du propre de la messe 1, Cycle de Noel (Stockholm, 1975)
• G. Bjorkvall, G. Iversen & R. Jonsson (eds.), Corpus Troporum III: Tropes du propre de la messe 2, Cycle de Paques (Stockholm, 1982)
• M. Sodi & A.M. Triacca (eds.), Missale Romanum: Editio Princeps (1570) (Vatican City, 1998)
• D. Hiley, Western Plainchant: A Handbook (Oxford, 1993), trope chapter

Predictions

No prediction registered yet.