Renaissance Flemish master Josquin des Prez made one of the most important aesthetic breakthroughs in Western musical history.Although it is a bit simplistic to state that Josquin (his fame was so widespread that he became known by only one name, like Cher) invented the identification of the minor keys with the more dolorous emotions, his sensitive ear-to-heart connection

broke the standardized Gregorian rules that had guided composition for a thousand years. And as a Catholic, his possessed profound influence in the Protestant church, especially since his most ardent exponent was a contemporary composer of hymns named Martin Luther.

The crowd at St. Bartholomew’s Church Sunday enjoyed the work of this granddaddy of all Mass composers as part of the church’s Summer Festival of Sacred Music, which offers a different setting of the Mass, from both sides of the Atlantic and from many eras, each week through September 17. Anyone willing to learn the rarely taught canon of religious music might want to consider spending Sunday mornings at this significant festival.

Josquin died in 1521 but his most famous setting, “Missa Pange Lingua,” is actually based on a hymn celebrating the transubstantiation, composed in the 13th–century by St. Thomas Aquinas and traditionally performed on Holy Thursday. This musical building block, called the cantus firmus, derives from an ancient Roman legionnaire’s marching song.

Music director William K. Trafka framed the Mass outstandingly. Three versets on the “Pange Lingua” by Nicolas de Grigny, rather than the traditional introductory march, served as the opening organ prelude. This trio of poetic pieces helped to establish our collective thoughts, from majesty to contemplation, and, finally, to mystery. The third of the little essays recalled that specifically French take on the ultimate unknowable, so powerfully expressed in much of Olivier Messiaen’s organ music.

Visitors to St. Mark’s Cathedral in Venice immediately notice the two prominent lofts in which the Gabrieli family invented the concept of the double choir.Physically, the music separates there, one voice answering or echoing another in the first attempt at stereophonic sound. Hans Leo Hassler, who traveled to Venice from Nuremburg and eventually retraced his steps to assist in founding the national German school, was one of the acolytes of the Gabrielis. The St. Bart’s choir offered Hassler’s powerful anthem “Cantate Domino” in vibrant polyphonic style.That the group sang this showpiece, moving the melody almost visibly, in the front center of the cathedral, proved notable.

Their placement was important because the group performed the des Prez Mass itself over to stage right, a humbling choice perfectly appropriate to this gentle, quiet, devotional work. They performed the opening Kyrie arrestingly pianissimo, commencing almost inaudibly and displaying the simplicity of its line. This humble beginning belied the complexities of the exultant Gloria to come, a movement so ingeniously wrapped around itself that it can express the infinite.

Of course, service occurred within the Mass, and I was struck by the contrast of the voices of the celebrants and those of the choir. After the recital of the Great Thanksgiving, the floating, seraphic female sounds of the Sanctus achieved otherworldly status instantaneously and introduced an elongated, memorable melisma on the line “pleni sunt caeli et terra gloria tua.” Male voices entered only for the final Hosanna. The choir sounded truly inspired in this section; this was tone painting of a most subtle hue.

The mirror image of the Sanctus is the Benedictus, with its quiet lower male voice ultimately leading to the gentle, concluding Agnus Dei, and the cessation of this groundbreaking work of religious music. Without Josquin, there would be no tears of Christ in the Bach passions and perhaps no classical music as we have come to know it. But for all of us, both Josquin and dedicated institutions like St. Bartholomew’s are a godsend.

Summer Festival of Sacred Music at Bartholomew’s Church (51st Street. at Park Avenue, 212-378-0222) through September 17.