Among the remarkable sacred compositions of Orlando di Lasso (1532-1594) are his unique and atmospheric settings of the Propers of the Mass for the feasts of Christmas, Easter, Pentecost, and Corpus Christi, first published in 1574 as Officia aliquot de praecipuis festis anni. In this recording project, the Propers (polyphonic settings of the specific liturgical texts "proper" to each feast)-Introit, Alleluia, Sequence, Communion-appear in correct chronological order and are interspersed with movements from some of the lesser-known and very beautiful Mass compositions by Orlando di Lasso.