A parchment bifolio which had been repurposed as the cover of a 1533 account book (as indicated by a former Klosterneuburg Stiftsarchiv shelfmark and year written in the margin of one leaf: RB 31/7 1533 – i.e., Rechnungsbuch). Its individual folios are numbered 43 and 46 in Roman numerals using alternating blue and red letters. Voice part texts begin with filagreed initials alternating red and blue. This bifolio was originally adjacent to the center bifolio of a gathering, judging by the numbering of the two folios, and must have come from a musical manuscript that had at least 48 folios (presuming gatherings were quaterns). It contains seven three-part Latin motets, or fragments thereof (three motets are complete, and four are incomplete), in Ars Antiqua style. Notation is on red 4-line staves with unlabeled tenor parts. The two leaves are currently referred to as 1 and 2 by their host institution (corresponding to XLIII and XLVI, respectively).

Of the three complete motets transmistted in the source, two appear to be unica (Elyzabeth Zacharie / Clausit sterilis / [tenor] and Ad hec Virgo / Ad Mariam / [Veritatem]) and one has concordances in the English sources Worcester and Lwa 33325 (Pro beati Pauli gloria / O pastor patris summi gregis / [Pro patribus]). Of the four incomplete motets transmited in the source, two appear to be unica (... / ...res age tutus eris / [Veritatem] and ... de via nos tuearis / Ave virgo / [Eius]) and two provide concordances with compositions known from Bamberg and Mo (Depositum creditum tibi / [Ad solitum nomitum] / [Regnat] and Post partum virgo mansisti / Ave, regina gloriae et angelorum / [Veritatem]).

This fragment was discovered by Eva Veselovská as part of the Institute of Musicology of the Slovak Academy of Sciences’ Recycled Medieval Musical Fragments of the Augustinian Abbey in Klosterneuburg project and is published at the Medieval Music Manuscripts from Austrian Monasteries (MMMAM) database (external link to images, above).