The library of the Cistercian monastery Zwettl owns five paper folios (390x290) of a former choir book with polyphonic music, which probably were written in about 1450. Peter Wright identified Johannes Lupi, musician and priest in and around Trent from 1447 to 1467, as scribe of the codex. Lupi is also main scribe of the first part of TrentC 87 and of the second part of TrentC 92 (The Com­pilation of Trent 871 and 922', in: Early Music History 2 (1982), 237-71). Possibly the original music manuscript was copied in Basel-Strasbourg region. Afterwards at least parts of the codex were used as pastdowns in book bindings. In this way some of the fragments, embedded in incunables, came to Zwettl. So the use of the former choir book in Zwettl can be excluded.

After Kurt von Fischer had discovered and documented the fragments in the mid-1960ies (Neue Quellen zur Musik des 13., 14. und 15. Jahrhunderts, in: Acta Musicologica 36 (1964), and they were presented at the exhibition Nieder­österreichische Landesausstellung in Zwettl in 1981. After that date they have disappeared for about 30 years (see also DIAMM with further literature). After some researches in 2012 I asked the Zwettl librarian to have a closer look at the library’s collection and indeed he was able to re-discover the lost folios. Now we are able to present color images of the reconstructed full pages for the first time.
Many thanks to P. Gregor Bichl, prior of Zwettl monastery, for the permission to use these images at our website.