While it is usually quite difficult to assign even vague dates of composition to Palestrina's masses (we have dates of publication for about three-quarters of them, and precious little else), his sole entry in the Requiem Mass genre, the four-voice Missa pro defunctis—the title means nothing more esoteric than "Mass for the Dead"—, is probably a very late work, and may actually have been written as music for the composer's own funeral. The Mass was published in 1591, having been added to a re-issue of a collection of masses, Palestrina's first such publication (hence its title, Liber primus, or "first book"), originally issued in 1554; while it is possible that the work existed for some time before being added to the Liber primus, it seems far more likely to have been composed during or shortly before 1591. The Missa pro defunctis is among Palestrina's most invaluable additions to the literature, showcasing his extraordinary ability to adapt and paraphrase pre-existing plainsong melodies to better suit his own brilliant polyphonic needs.

Palestrina composed polyphony for four sections of the mass for the dead—the Kyrie, Offertorium, Sanctus, and Agnus Dei-and it is up to the performers to supply, as chant, the remaining portions (namely the Requiem aeternam introit, and possibly a Gradual, Tract, and Communion).

The Kyrie is in the traditional three-part form, consisting of a Kyrie eleison, a Christe eleison, and a second Kyrie eleison. The hypolydian mode is in effect here, but to modern ears the music sounds little different from F major. Both the first Kyrie eleison and the Christe eleison take a rising filled-in fourth motive as their initial, imitative starting point; it is fitting that the first tenor, who was last to join the texture in the opening (with an exact restatement of the cantus' first eighteen pitches), is allowed to begin the Christe. The second Kyrie begins with a point of imitation on a striking descending fifth (extracted right from the Kyrie plainsong).

The Offertorium is on the text Domine Jesu Christe, beginning with a plea that the Lord "deliver the souls of the faithful dead from the torments of hell". The text is laid out in two sections of roughly equal musical length: the first portion deals with the first ten lines of text, the second with just the last six-clearly, Palestrina is putting great musical weight on the final supplication to the Lord to offer new life to the departed.

At the beginning of the Sanctus, Palestrina shows how well he understands the maxim that "less is more": by a simple, subtle alteration of the traditional Sanctus chant (the descending major second neighbor-note figure that begins the chant is changed to the more affected minor second, A-G sharp or, in the bass and alto, D-C sharp), both the expressive tone and the local tonal implications of the melody are changed. A substantial Benedictus is appended at the end of the Sanctus.

There are, quite traditionally, three separate settings of the Agnus Dei text, each of which commences with a chromatic neighbor-note figure that probably has its origin back in the Sanctus. Agnus Dei I and II, though quite distinct from one another internally, both conclude in a manner that shows how close the ancient mixolydian mode could get to modern G major. The third Agnus Dei, to whose text is appended the word "sempiternam", or "eternal", gives us a more truly modal close, abandoning the chromatic F sharp in favor of F natural.

© Blair Johnston, Rovi