An Altus partbook from a set originally of four(?) volumes; 11 numbered masses, all copied anonymously. The ninth (to the BVM) was copied with its propers, and the quinta pars of this mass is copied in I-PCd s.s. (2). The 4 Willaert masses come from his 'Liber Primus' of 1536, but are not copied in the order of the print. Each of the books was bound with some of masses 9, 10 and/or 11 out of sequence at the front; the misbound pages differ in each book.

Copied by two main scribes, who also wrote parts of PiacD (2), (3), (4), and (5); one Mass in the Altus book copied by a third scribe. Probably copied in Piacenza.

Original parchment covers cut from 16th-century chant manuscript

black void mensural

Other numberings: Original numbering of pieces, 'Missa Prima,' … 'Missa Undecima', Several Masses now out of proper sequence due to misbinding or careless arrangement by scribes.

original ink foliation 1-19 + new pencil foliation 1-7 + original ink foliation 13-77 (last folio unnumbered)

paper

11 Masses (1 includes Proper sections)

(Berchem)-1, (Berchem/Jaquet of Mantua)-1, (Hesdin)-1, (Jaquet of Mantua)-2, (Willaert)-4, anon-2

3 paper partbooks of an original 4 (D-ii + 84 + i folios, A-ii + 91, T-i + 81 + i), 160 x 220. D book has original ink foliation, 1-75 (number "6" omitted) + new pencil foliation, 1-7 + original ink foliation, 13-76 (last folio unnumbered); T has original ink foliation, 80-81 + 1-79. Original numbering of pieces, "Missa Prima," . . . "Missa Undécima" (several Masses now out of proper sequence due to misbinding or careless arrangement by scribes).

Original parchment covers cut from 16th-century chant manuscript. No index. Copied by two main scribes, who also wrote parts of PiacD (2), (3), (4), and (5); one Mass in A book copied by a third scribe. Some small inked calligraphic initials.

Mid 16th century. Probably copied in Piacenza.