Josquin's Missa Ave maris stella is a relatively early that must have been composed sometime between 1495 and 1505 when it appeared as the opening work in the second book of Josquin's Masses published by Ottaviano Petrucci the Venetian master printer and publisher. It's a cantus firmus work in other words Josquin used the melody of another piece of music as the musical foundation for this setting of the Mass. As the name Missa Ave maris stella might lead you to expect the cantus firmus Josquin used was the Dorian mode Marian hymn of that name and which I include as the starting track in the recording below.
This hymn which was appointed to be sung at First Vespers on feasts of the Blessed Virgin Mary was very popular and very greatly loved. Even as Gregorian chant there are six settings of it that I know of and there could well have been more there's also a very well-known setting by Dufay. Not being one to pass up an opportunity Josquin's setting makes heavy use of it as a cantus firmus. You can hear it throughout the Mass both as a structural voice subject to embellishment or as the foundation for some highly developed imitation. It's a really stunning setting in which Josquin somehow manages to combine some quite severe contrapuntal writing with intensely declamatory treatment of the text and numinous euphony. It's a compositional tour de force in which Josquin clearly set out to show what he could do and I find it very difficult to pick out one highlight over another so I'll confine myself to mentioning just a few points.