The music preserves sections two and three of the Agnus Dei text, including the ending; the opening section is lost, and was perhaps on a facing page. It is likely to have once formed part of a choirbook in cantus collateralis layout. The spacing of textual cues and rests at the beginning of new sections indicate the absence of other vocal lines and a melismatic style consistent with English polyphony of the late fifteenth or early sixteenth century. When in position in the binding the vocal part continued from the rear of the current binding to the front, with the middle of the leaf hidden in the spine. It has now been removed by the record office conservation department. The music alternates between cut-C and cut-O mensuration. The C4 clef, B flat signature, and contrapuntal movement to cadences on F suggest that this is a tenor part of three or four vocal lines, but not the lowest voice.

The paper leaf is currently wrapped around the Whitby Abbey Coucher book, and the fragile nature of the binding means that comments much remain provisional until the leaf is removed from the binding for conservation purposes. Some of the music has been lost or damaged (trimming, water damage, rodent damage); most of the extant music is still legible, if difficult to read in the manuscript’s current state. The volume passed to WYAS from the former owner, E. R. F. Compton, Newby Hall, where it was held as MS 2907.

Late 15th-century binding, relatively informal, using a parchment Papal bull lined with the paper as filling. Contents of host volume are transcripts of documents mainly relating to Whitby Abbey, from original documents dating from 1293–c. 1460. They include a valuation survey of lands, rents, and tithes held by the Abbey c. 1460, transcripts of an Inspeximus charter of Henry VI to the Abbey of Whitby (3 December 1445) reciting previous grants, and a list of the Kings of England from Egbert to Edward IV. The binding’s features suggest that the materials were grouped together before the Reformation, so not long after the music was in use, and this may support a provenance of Whitby Abbey, or one of its dependent cells, for the music itself.

Void notation with black full coloration. Mensural notation including cut C and cut circle. Some elements of the hand resembles that of Ybi Mus. 1 (the York Masses), but the page size and stave depth are of smaller dimensions than that source. C4 clef and B flat signature.

Staff height 12–14mm. C4 clefs visible.

None. The reverse of the leaf is currently hidden, but does not appear to have music on it; there is some evidence of ruled stave lines on the reverse.

No initials or decoration

Lisa Colton acknowledges the initial work undertaken on this fragment by Jason Stoessel, and by Susan Harrison, who it drew it to their attention.