A partbook designated 'Contratenor' on a large number of the pages, although some of the parts appear to be for other voices. Although early descriptions of the book suggest that its four sections are survivors from a set of what was originally six books, now bound together as a single book, there is no reason to suppose this is the case, particularly as the book is held in contemporary limp vellum covers, indicating that this is the form it was intended to take. It is more likely that this is simply a collection of their own voice parts belonging to an individual, and was either never part of a partbook 'set', or this is a surviving partbook from a lost set.
A front, unnumbered section, consists of 4 songs by Byrd, for 5 voices; The first numbered section consists of English anthems and songs by Byrd and others, 5 voices 'and 6 if you will', numbered 1-36; The next section has motets and other music for 5 voices by Byrd and others, numbered 1-57; and the final section is of motets, canticles, instrumental pieces, and an Italian madrigal by Alfonso Ferrabosco senior, for 6 voices, numbered 1-30.
The collection, if complete, would have ranked as one of the most important of all secular Elizabethan sources because of the wide and representative cross-section of so many musical genres, sacred and secular in its 131 works, and the many unica it contains. The concordances that can be traced show this to be an authoritative source generally, and particularly for the works of William Byrd. Original numbering of pieces in three series: 1-35 (omits some pieces); 1-57; 1-30 (some numbers missing, but all pieces included in enumeration).
First and third series contain 6-voice works; second series contains 5-voice works. Copied by several scribes. Some pieces have text incipits or titles only. Of English origin; possible connections with Sir John Petre (1549-1613), of Ingatestone, Essex. Petre was a neighbour and patron of Byrd. Later owned by Oxford University Music School; passed to Bodleian Library in 1885.
The name Peter Gifford is written three times in a contemporary hand on one of the rear endpapers.