Mass in C minor, K. 427
Wolfgang Amadeus Mozart  (1756-1791)

[1783]

Mozart grew up in Salzburg surrounded by church music in that epicenter of Catholic life in Austria. After the excitement of touring as a child prodigy, he found it unbearable to be back home working alongside his overbearing father for the church, at a time when it was controlled by a particularly nasty archbishop. Despite his best efforts to find a job elsewhere, Mozart was still stuck there at the age of 25, until he finally took the risk to break ties with Salzburg and try freelancing in Vienna.

Life in Vienna proved transformative for Mozart. Guided by an older patron, he did a deep dive into the music of Bach and Handel, at a time when their contrapuntal style was considered hopelessly old-fashioned. Mozart also had space to pursue his greatest passion, opera—which brought him back into the orbit of a powerhouse theater family, the Webers. Some years earlier, he had pursued a romance with soprano Aloysia Weber; that relationship had fizzled, but now it was her younger sister Constanze who caught Mozart’s eye. They ended up marrying in 1782, over the objections of Mozart’s father.

In what turned out to be his only return visit, Mozart brought his new bride to Salzburg in 1783 to introduce her to his family and smooth over any hard feelings. It was in connection with that trip that he composed his “Great” Mass in C minor, for reasons that are not entirely clear. Maybe it was a peace offering to the father and the church he abandoned; or it might have been designed to show off his wife (who sang the soprano solos) and prove her merit; or perhaps it was an act of faith, coming after a point when Constanze seemed to be at death’s door.

Mozart began composing the mass in 1782, and at the beginning of 1783 he wrote to his father that he had “half a mass which is still lying here waiting to be finished.” And despite his ability to write with astonishing speed, it still wasn’t complete when he presented it during a Sunday service in Salzburg that October. He reworked some of the material into a later cantata, but otherwise he never returned to this ambitious, unpaid project.

All of the musical cross-currents that make Mozart’s “Great” Mass so fascinating are present in the opening Kyrie. In the choral setting of the words “Kyrie eleison,” the pulsing harmonies in the orchestra and contrapuntal layering of the voices channel the heft and grandeur of Bach. Then, with a seamless key change and a drastic thinning out of the textures, we find ourselves in one of those sweet, ambling andantes that Mozart loved so much as a vehicle for impossibly long and weightless phrases, as the solo soprano sings “Christe eleison” in a manner lifted straight out of Italian opera.

Another aspect that stands out is the sheer sonic power of Mozart’s setting, featuring an orchestra stuffed with brass and timpani that makes sections such as the Gloria and Sanctus resonate with extraordinary brilliance. Bridging his upbringing in the church and the showmanship of his prime years in Vienna, this “Great” Mass stands out as a singular treasure in Mozart’s vast output.

Flute, two oboes, two bassoons, two horns, two trumpets, three trombones, timpani, strings