A large bifolio fragment of a codex, discovered in October 2019 by Giuseppe Mascherpa and Federico Saviotti, and restored in winter 2020. The fragment had been re-used as the cover for the canon law essay Tractatus de irregularitatibus by Bartolomeo Ugolini, printed in Venice in 1601. It contains 2 virelais and 2 rondeaux all in 2vv with untexted Tenors, and 2 texted voices of a Credo probably originally in 4vv; all are unica. These are on f.1rv, while f.2rv is ruled but has no music; it is possible therefore that work on the planned codex may not have been completed. Text and music copied in the same ink, possibly by a single scribe.

Scatola 4, the case in which the fragment is kept, also contains 3 parchment strips from the book covering which relate to the large fragment. The reconstructed bifolio would have been larger even than Squarcialupi.

A second bifolio from the same codex was discovered by Anne Stone at the Biblioteca Trivulziana in Milan, also in 2019 (re-used as the binding of I-Mt 1759).

An ex libris in the book records that it was at some point in the Jesuits' library in Milan ("Domus Professae societatis Iesu Mediolani Inscriptus Cathalogo") When that closed in 1773 the book passed to the Braidense Library at the Palazzo Brera, and thence was donated to Pavia, presumably as a duplicayte, before 1780 when it is recorded in a catalogue there.

fourteenth-century black notation using dragmae, including an unknown form of ‘dragma brevis’; a case of half-coloration & an unusual treatment of coloration in a cadence.

fourteen red five-line staves with line spacing of 3.625 mm (though one stave is 6 lines)

The pages are not numbered; modern foliation.