Hierarchy classification:

1. top of the aat hierarchies
2. Objects Facet
3. Visual and Verbal Communication (hierarchy name)
4. Information Forms (hierarchy name)
5. information forms (objects)
6. document genres
7. [documents by function]
8. religious texts
9. liturgical texts

Anotations

Scope note:

Books of tropes, which are introductions to liturgical chants or interpolations or elaborations to the text of the Catholic Mass. They were discontinued when the Roman Missal was revised under Pius V (1566-1572).