Musicians tend to tiptoe around Ludwig van Beethoven's monumental Missa Solemnis, which crowns the Minnesota Orchestra's 2008-09 season this week. Scholars and performers who have spent much of their lives in Beethoven's company, who have grown intimate with his symphonies and chamber music, are apt to proclaim the work's greatness, but their proclamations often sound ritualistic. The music, more honored than loved, remains distant and enigmatic.

Composer/critic Virgil Thomson once sniffed that he'd rather ponder the piece than hear it: "Much of its detail is weak," he wrote, "and does not carry." It's probably the only major score by Beethoven that deserves to be labeled "underperformed."

Any effort to get closer to the Missa Solemnis, written over more than four years, must begin by acknowledging its strangeness. The work presents itself as church music, but neither in ecclesiastical nor in secular settings does it seem entirely comfortable. As musical philosopher Theodor Adorno observed, it doesn't sound like the Beethoven we think we know; it mingles symphonic, operatic and archaic church styles, the latter painstakingly researched by the composer. Its demands on performers, singers especially, are extreme: Beethoven pushes the voices cruelly high, sometimes for extended stretches. The waspish Thomson can almost be forgiven for thinking the piece loud and overlong.

Strangest of all, perhaps, is the work's core project. Why would the 48-year-old Beethoven -- who, though raised a Catholic, was deeply idiosyncratic in matters of religion and certainly no churchgoer -- pour himself into a musical setting of the Ordinary of the Mass? And how did that setting, despite the limitations seemingly imposed by the text, take on the character of an intensely personal testament, a searching summation of his art and convictions?

New wine in old bottles

The Beethoven who began the mass in 1819 was Europe's most celebrated composer, rivaled only by the wildly popular Rossini. Eight of his nine symphonies and 29 of his 32 piano sonatas were behind him; he had transformed these genres, and others, almost beyond recognition, infusing them with a forcefulness and a subjectivity beyond anything in music's past. But his output had slowed to a trickle. He was completely deaf. His miraculous late string quartets were wholly unforeseeable. It was easy to suppose that his creative career was at an end.

His private life, as usual, was a shambles. Son of an exploitative, alcoholic father, he had seldom known tranquility. Messy relationships were the norm, failed romances a specialty. He had endured Napoleon's bombardment of Vienna in 1809, holding pillows over his ears to preserve what little hearing he then had left. He changed dwellings repeatedly. His finances were precarious, his personal hygiene abominable. And he was enmeshed in a protracted legal battle for custody of his nephew Karl.

This was the proud, flawed, visionary man who embarked on the composition of a mass to celebrate the installation of his pupil and patron, Archduke Rudolph of Austria, as archbishop of the city now called Olomouc, in the Czech Republic. (Rudolph seems to have been the addressee of the words Beethoven famously inscribed over his Kyrie: "From the heart -- may it again go to the heart!") The work soon mushroomed in scale and ambition, outgrowing its initial stimulus, becoming a colossal meditation on faith and doubt -- a fiercely individual probing of questions usually assumed to be the property of theologians, not musicians.

Any short list of the Missa Solemnis' most memorable passages would surely include the setting of "Gratias agimus tibi" (We give thee thanks), the overwhelming conclusion of the Gloria and the long, ethereal violin solo in the Sanctus. But for me the most extraordinary moments come near the end, in the "Dona nobis pacem" (Grant us peace) section of the Agnus Dei, where the profane world bursts in upon the sacred space of the mass. Sounds of war -- drums and trumpets -- invade the music, which becomes, in the composer's words, a "prayer for outer and inner peace." From a life frequently in turmoil, Beethoven had learned the preciousness of peace. His work can help us do the same.

Larry Fuchsberg writes frequently about music.