An unnotated Cistercian Breviary, dated between 1266 and 1300 and probably from Vorarlberg in Austria. There are three, later musical additions across a blank opening (fols. 284v–285r), in Franconian measured notation. The music seems to have been inscribed in the fourteenth century, and possibly in Bohemia.
This source was first discovered and reported by Dominique Gatté in 2017, who identified a concordance for the two-voice Benedicamus Domino trope In hoc festo gratissimo (on fol. 285r) in the Codex Las Huelgas (E-BUlh s/n). In fact, CZ-Pu MS XXIII.G.60 and E-BUlh s/n represent two isolated examples, in rhythmically-measured notation, of the famous ‘Stimmtausch Hymn’, whose best-known early instantiation is that copied ca. 1100 in F-Pnm Latin 1139 (here on fol. 32r–v, with the text Deus in adiutorium intende laborantium, and notated successively as a melody, rather than in two-voice score).
The first system of fol. 284v of CZ-Pu MS XXIII.G.60 preserves a further (untroped) Benedicamus Domino composition using voice-exchange or Stimmtausch techniques, this time in three voices, and in a short-hand notation (giving just the first phrase, followed by a cue) in three-voice score. This three-voice Benedicamus Domino is known also from E-BHUlh s/n (fols. 25v–26r) and I-Fl MS Pluteus 29.1 (fol. 47v).
A further Benedicamus Domino setting on fol. 284v of CZ-Pu MS XXIII.G.60 may also be polyphony, with two voices notated successively, but no concordances can as yet be identified.