Two late 13th to early 14th century vellum leaves from a musical manuscript mounted upside down as front and rear flyleaves (formerly pastedowns) in a 1482 incunabulum (Lumen anime, seu Liber moralitatum). There is a bit of offset of music onto the front binding board, though the music on the leaves remains largely legible. The flyleaves contain four motets of English provenance; it is possible that these are two leaves from an alphabetical codex, with one leaf each from E and V. Only one item has a concordance elsewhere at the time of this entry: Eterne/Dona, which is incomplete in this source, though its quartus cantus (for which space had been allotted) survives as a fragment in US-Cu MS 654 appendix.

This source was first described in 2023 by library curator Mary Clayton-Kastenholz in an online seminar for the Society of Bookbinders.