Many composers are more renowned for one genre of music over another: Chopin's piano music, Verdi's operas, Mahler's Symphonies, Bach's organ music. But Mozart mastered every genre he touched; he was the greatest composer of piano concertos, symphonies, wind and horn concertos, masses, string quartets, piano and violin sonatas, and much else.

Following the first opera of his maturity, Idomeneo, Mozart was obsessed with opera. His collaboration with Lorenzo da Ponte yielded three works, Le nozze di Figaro, Cosí fan tutte, and Don Giovanni, which stand out as three of the greatest works in the operatic canon‹the centerpieces of Mozart's life, operas unprecedented in the depth of their humanity and beauty. Le nozze di Figaro (henceforth, The Marriage of Figaro) gives voice to universal themes and images using the best possible means: laughter. It is an opera whose title is often uttered with a sigh, like the name of an old and beloved friend. Mozart's genius continues to cast a spell over us.

But genius is not a fixed image; it is abstract perpetual motion, a kaleidoscope. Mozart's genius continues to mystify and inspire, to the point that he has become all things to all people: for many he is enlightenment itself, music's great philosopher; to some theologians he is proof of the presence of deity in humans. To others he is a miscreant, a bawdy and brilliant punk. And depending on who's doing the looking, he's all of those things, starting from a shockingly young age. As playwright Wendy Wasserstein memorably opined, "Because of Mozart, it's all over by age seven."

But who could not be impressed by the 12-year-old Mozart hearing‹just once‹the composer Allegri's complex polyphonic Miserere in the Sistine Chapel, and dictating it into his manuscript book, without error, from memory?

Yet Mozart didn't write in an ivory tower. The Marriage of Figaro is his most human work. Gone are the Greek Gods and formulaic legends depicting royalty as ever-clement and magnanimous. This opera's characters were a mirror of society, from master to servant. It is a work of perfect balance: humor and pathos, politics and love. The bored and unhappy upper-class characters are balanced by servants who are just awakening to the joys of love despite the confines of their class. The wonder of young love, or the melancholy remembrance of it, permeates the opera. Musically, the beautiful and formal courtly music is balanced with tunes of folk-like ease. There is an endearing universality to the drama of this opera, and the passing of 220 years has done nothing to dim its youthfulness.

But, of course, if all of the above were the secret to the success of The Marriage of Figaro, we would see regular revivals of the Beaumarchais play on which it is based. The play Le Mariage de Figaro, legendary for having helped light the fire under the cauldron of the French Revolution, has become a part of political history, but we rarely see it in theaters today. The 18th-century ruling class found its depiction of the servant class dangerously subversive, and it was as controversial, and therefore as popular, as any documentary film of recent years. Still, it has largely disappeared except in the classroom.

It is, of course, Mozart's music that has kept The Marriage of Figaro alive through the centuries. The score of Figaro presents such perfection of characterization, such elegance, wit, and immediacy that each time one hears it, it is fresh. It is fired by the most elemental of human characteristics: curiosity. Mozart takes small thematic materials and develops and plays with them, as though they are a puzzle to be solved, with constantly renewing ingenuity and depth. The opera's familiar overture develops out of a comically simple five-note flourish, and sends us laughing and cavorting through the complex score, Mozart's creativity feeding on itself, until the end of the opera, when the Count tenderly asks for his wife's forgiveness and Mozart gives us one of the most serenely beautiful moments of art ever conceived. Between the D-major bookends of overture and finale, Mozart takes us through "un giorno di follia" (which means "a day of folly" and is in fact the opera's subtitle), the plot of which is a delightfully complex tangle that Mozart wraps in a virtuosic musical tapestry. Its humor, both visually and musically, is the humor of youth: disguises and tricks to the eye and ear.

Perhaps The Marriage of Figaro has endured simply because its music is so beautiful. But I suspect there is another reason: who among us cannot recall just one memorable day of our youth, whether real or imagined, which evolved into dusk, and during which we experienced disguises, jokes, tears, pain, forgiveness, and laughter at all of it by the time we slept? All too soon, of course, we learn that things don't always wrap up so neatly. Still, when it comes to the memories of our youth‹those memories that we sometimes alter to our liking‹that kind of Mozartian magic can exist.

Given my upbringing in a small Indiana town, my most Mozartian evening occurred in an unlikely time and place, far from Europe and America's musical centers, and early in my career, at a time of my own life that has formed part of the prism through which I view music.

From 1987 to 1991, I made multiple journeys to Shanghai in the People's Republic of China. The Shanghai of 2005 was unimaginable during those years when China was still very much in recovery from the Cultural Revolution, which had ended a little over a decade before. As part of an exchange program started by Kurt Herbert Adler, the legendary former general director of San Francisco Opera, I taught opera at the Shanghai Conservatory and I conducted the first Asian performances of Puccini's Tosca‹in Mandarin‹at the Conservatory in 1988.

In those years, rolling blackouts were common and expected in Shanghai, the infrastructure of the city not yet able to support its burgeoning population. As my class began one evening, the lights went out. The students fetched candles and oil lamps and within minutes we were underway. Several singers presented music, which I worked on with them while a few dozen other students listened. Through my stalwart translator, Gu Ping, I communicated all of the minutiae of information I was there to disseminate. Due to the Cultural Revolution, this was a generation of singers with almost no exposure to Western art of any kind, much less the demanding and grand abstraction of music. With several different young artists, I worked through several pieces of music. Shortly, it was completely dark outside; from our fourth-story classroom with floor to ceiling windows, we could see the glow of thousands of candles and lamps over a vast section of the city, and a blanket of stars‹usually invisible‹stretched out above us. We carried on. A shy girl, whom I had never seen before, came to the piano and handed me a ragged sheet of music, something I was quite surprised to see‹Mozart's "L'amerò sarò costante" from his youthful opera Il re pastore (The Shepherd King). I don't know if I've ever heard a young voice of more beauty and richness. The aria itself is another of Mozart's gems: the young shepherd king bestowing affection on a lover not of his social station‹a stock 18th-century text, but in Mozart's hands, a masterpiece of tenderness.

So we started to work.

"Do you know what the opera is about?" I asked, through Gu Ping.

I waited, expecting to hear the typical answer: a quick plot synopsis or basic translation.

The young girl thought very seriously for a moment and said to me, in slow and indelible English, "In this aria…I think…Mr. Mozart wishes peace on the whole world."

The sensuous dark beauty of that night, the utter youthfulness of all of us, the ravishing timbres of her voice, the curiosity, and her moving response to my excessively mundane question, have conspired over the years into a pristine memory, of which Mozart is always the centerpiece. I learned so much more on that single night than I ever could have hoped to teach.

Tonight's performance features some wonderful singers from Houston Grand Opera Studio, our young artist training program. My wish for them‹and for you‹is that there will be Mozartian magic tonight, the kind that no one ever forgets.

Patrick Summers is the music director of Houston Grand Opera.