P-Cua (Coimbra) Arquivo Distrital e da Universidade IV-3ª Gav. 44 (11)
This fragment contains chants for the office of Transfiguratio Domini, from the end of the first Nocturn to Lauds. As a feast introduced relatively late (9th c. circa), it lacked fixity, with "different chants [drawn] from [other] traditional feasts, like Christmas, Epiphany, the Easter season and even the Holy Trinity."
The present source gathers musical items from De Trinitate, Sabbato Hebdomadae 1 Quadragesimae and Commune Plurimorum Martyrum, with readings taken from the Gospels and from the hagiographies of pope Sixtus II and his deacons Felicissimus and Agapitus, as well as Cyriacus (only a few lines at the end of the fragment verso).
Inscriptions written no earlier than c. 1700, seen between the columns of the verso: Tombo de Pereiras, e anexas. / Pereiras V/. 260. / Tombo da Igreja de S. Salvador de Pereiras e suas annexas. / Nº 260 /. Fuller inscription at the bottom:
"Tombo da Igreja de São Salvador de Pereira, e suas annexas, São Tiago de Moldes, e Santa Maria de Remelhe, feito no anno de mil, quinhentos, sincoenta e um" [1551].
Other sources in the Cantus Database do not index the chants reported here as pertaining to Transfiguratio Domini, rather to one of the three other feasts mentioned. The two major notated Braga sources in which the feast also appears (P-BRs Ms. 28 and Ms. 34) share only a few chants with this fragment. Later, 16th c. text-only breviaries from Braga and Évora do have the same order of chants, although paired with different Matins readings. Such evidence hints at a complex net of liturgical interrelations.
The late inscriptions (see above) allow to cautiously localize the fragment as being held at a certain point either in the zone of Barcelos, some twenty kilometers West of Braga, or in Braga, whose See superintended the parish of São Salvador de Pereira. More in-depth analysis might ascertain whether it was also originally produced in the area.
For musicological reviews of Transfiguratio Domini, see Gábor Kiss, 'Candor est lucis aeternae: the "Transfiguration" of a New Feast and of an Alleluia', Studia Musicologica, 56/2-3 (2015), pp. 217-31 (from which the above quote is taken) and David Hiley, 'The Office of the Transfiguration by Peter the Venerable, Abbot of Cluny (1122-1156) in the manuscript Paris, Bibliothèque Nationale de France, fonds latin 17716', in Chant and its Peripheries. Essays in Honour of Terence Bailey, ed. Bryan Gillingham and Paul Merkley, Musicological Studies 72 (1998), pp. 224-240.