The Leiden choirbooks are six volumes of polyphonic renaissance music of the Franco-Flemish school preserved in the Pieterskerk, Leiden.
The books were compiled for the Pieterskerk's College of the Seven Liturgical Hours, a professional choir employed at the Pieterskerk, as at many large Dutch city churches during the 15th Century, to sing masses for the dead - or rather those of the dead rich enough to have had left bequests and endowments for masses to be sung for them. Leiden was the first city to acquire a professional college for these masses, c.1440. Rotterdam, Delft in both churches, Haarlem, Gouda, Alkmaar, and finally Amsterdam (as late as 1468) also set up dedicated "college" choirs.
The Liturgy of the Hours in major Dutch churches in the 15th Century was as follows:
Apart from the Leiden choirbooks almost no trace survives of the Seven Liturgical Hours repertoire. The Leiden books themselves were very nearly destroyed in the iconoclasm of 1566 when a mob burst into the Pieterskerk and ransacked it, but must have been securely locked away and survived.
Apart from works by renowned masters such as Clemens non Papa, Willaert, and Crecquillon, the books also include anonyma and compositions by less well-known Flemish and local composers.
The Egidius Kwartet is to record the major pieces from the 6 choirbooks in 6 annual 2CD releases from 2010-2015.