Pergolesi was never more popular than in the first generations after his early death, when his intermezzo La serva padrona (The Servant Mistress) sparked the Querelle des Bouffons in Paris and publishers found that attributing even the most lackluster music to Pergolesi would guarantee sales. Dying young may have placed the ultimate limit on his personal success, but it only enhanced Pergolesi’s posthumous romance. His intimate deathbed piece, the Stabat mater, grew with his legend: In 1776 Hiller arranged it for four voices, added woodwinds, and “improved” the harmony; Paisiello and Salieri further augmented it; and by 1831 Alexey L’vov found that only full orchestra, chorus, and soloists would do for the imperial court chapel in Russia.

In purely functional terms however, Pergolesi’s Stabat mater is vocal chamber music, not intended for public church services but for the private worship of a noble fraternity in Naples, the Cavalieri della Virgine de’ Dolori. This brotherhood had been using Alessandro Scarlatti’s Stabat mater for their Good Friday observances for a generation and desired a more stylistically up-to-date replacement.

Pergolesi accepted the commission, but was in poor health, as he seems to have been for most of his life. Pergolesi’s two brothers and sister died in infancy, and the fact that he was confirmed when barely a year old suggests that he may have been critically ill himself at the time. A sketch by the Roman caricaturist Leone Ghezzi, done probably about two years before Pergolesi’s death, shows the composer with a deformed left leg, and early accounts say he had tuberculosis.

In any case, his condition seems to have worsened in 1735. Pergolesi scored a modest success in Naples with the three-act comedy Il Flaminio, staged at the Teatro Nuovo in the autumn, but by November he was too weak to complete a serenata commissioned for the wedding of Prince Raimondo di Sangro. Early in 1736 he withdrew to the Franciscan monastery in the spa town of Pozzuoli, near Naples. Judging from the dispositions he made of his limited property, he did not expect to live long, and he died March 16, barely two months after his 26th birthday.

He did, however, complete the Stabat mater and a Salve Regina while in the monastery – it is uncertain which was his final work. Much of this account is unconfirmed legend, although the stories began almost immediately, and Alfred Einstein states that the manuscript of the Stabat mater shows clear signs of haste, at least in the final movement.

The liturgical use of the 13th -century poem “Stabat mater dolorosa” has varied over the centuries, and it has been set in the prevailing styles of every era. In Italy in the 18th century, the text was quite often set as a sort of chamber cantata with its own tonal unity, as in the setting by Pergolesi. The metrical poem is composed in pairs of three-line versicles rhymed aab - ccb, but in practice composers split the verses freely.

Indeed, Pergolesi creates an amazing variety of sounds and moods from this very formal text and his quite restrained forces. (Two solo voices, strings, and, in this edition, a continuo group of organ and lute. There are often only three real parts, with the violins doubling the voices and the violas doubling the bass line.) The first four movements of his setting each take only a single three-line versicle. The fifth movement is a big duet for which Pergolesi uses three versicles, the first two set in C minor as a cantilena over a throbbing accompaniment. Pergolesi begins the third versicle almost as an operatic cabaletta, changing meter and key, although he brings it back quickly enough to C minor, even including a strange noodling passage over a dominant pedal before the close.

Two arias follow, returning to Pergolesi’s main aria texture of unison violins doubling the voice part, with frequent recourse to word painting. Pergolesi suggests the contrapuntal rigors of a three-voice fugue in the ensuing duet, however, allowing the bass line to participate. The composer takes the opportunity to paint the word complaceam (“might please”) with burbling musical joy and aspiration.

The ninth movement is a large duet in E-flat major using five versicles. The ensuing alto aria, in G minor, sets two versicles, each different but related, and each imbued with starker drama of Passion music. The tenth movement also sets two versicles, the first as a soprano solo, the second as a duet. The dancing jauntiness of this piece, in B-flat major, reflects joy and confidence in the protection of the Virgin and the cross, leaving the observer “cherished by grace.”

The final number is a duet, back in the F minor of the opening and the somber atmosphere of the Passion. The voices sing this final prayer on points of imitation against an accompaniment of flowing arpeggios. The Amen is the point where a grander piece would break into a double fugue, and Pergolesi fakes one quite ingeniously despite working with only three real parts, the violins again doubling the voices. There is even a miniature, proto-Beethovenian coda.

For musical progressives, this was the most stirring music imaginable. Padre Martini was only one of many conservatives, however, who found little to distinguish the Stabat mater musically from the comic La serva padrona. The musicologist Johann Nikolaus Forkel wrote that the “atmosphere of piety and devotion with which [Pergolesi] has been able to enshroud this composition has deceived the uninitiated amateur with its hypocrisy, and has won a fame for itself which is quite undeserved.”

That was a rather bold statement from one of the early biographers of Johann Sebastian Bach, since Bach himself – hardly an uninitiated amateur – valued the work highly enough to arrange it for his own use in Leipzig within ten years of its composition. Bach adapted the penitential Psalm 51, “Tilge, Höchster, Meine Sünden,” for the German text, and took Pergolesi’s music mostly as he found it. He did liberate the viola part from its doubling of the bass line, and made rhythmic alterations as needed for the new text. He even composed new music where he felt the need, most notably extending Pergolesi’s Amen fugue to twice its original length.

That should be the ultimate imprimatur, if any were truly needed. The gracefully balanced phrases, the clarity, and the operatic expressivity that so entranced the most modern musicians of the time were built over solid Baroque forms and enriched with enough polyphonic detail to please the most fastidious of masters. Bach surely appreciated both the pre-Classical lyrical plasticity and the old-school fundamentals that have continued to sustain this piece so popularly in the repertory.

Program Notes by John Henken