Choralis Constantinus II contents

The contents of Choralis Constantinus II are arranged in chronological order, beginning with Christmas (December 25) and ending with the Conception of the B.V.M. (December 8). Most of the feasts fall on fixed dates, but those that are dependent on the date of Easter (Easter, Ascenion, Pentecost, and Corpus Christi) have variable dates.

Most of the masses include four liturgical items: introit, alleluia, sequence, and communion. During Lent, the alleluia is replaced by a tract. For that reason, Mass 5 (Annunciation), which always falls during Lent, has a tract and no alleluia. Mass 4 (Purification) may or may not fall during Lent; Isaac therefore provided both an alleluia and a tract for it. Mass 5 (Annunciation) lacks a sequence, as well as the alleluia. Mass 6 (Easter), the most important feast of the year, has a gradual in addition to the other four items.

The feasts for which Isaac provided music in Choralis Constantinus II were of different levels of importance in other places. The number of pieces from the collection that appeared in other sources (by whatever route of transmission) therefore varies considerably. The pieces with the most copies are those from the period of Christmas through Pentecost (Masses 1-8). Those for the local Constantine saints Geberhard, Pelagius, and Conrad appear only in contexts where they are assigned or adapted to other feasts. The feast of Saints John and Paul (Mass 11; not the same saints as the ones with the same names celebrated in Masses 10 and 12) evidently had little currency outside of Constance, since no copies of its music survive outside of Choralis II.

Some places (notably Brno and Bártfa) evidently did not use polyphonic communions in their liturgies, since communions are mostly lacking from the extensive sets of Choralis II material in the sources copied for those places.

The contents of Choralis II are as follows. Other sources are shown in the links.