In December 2004, a performance of Bach’s Christmas Oratorio took place in St. Bartholomew’s Church. This was part of “Cantatas in Context,” a series started by Mary Dalton Greer, a scholar and conductor, in 2001. The idea is to perform Bach’s cantatas according to the liturgical calendar.

In any case, there was a performer who stood out from the others in that Christmas Oratorio: the mezzo-soprano, Brenda Patterson. A Seattle-born graduate of the Juilliard School, she proved herself the genuine article: a real Bach singer. She was both correct and moving, solid and spiritual. The review published in this newspaper was entitled, “Discovering Brenda Patterson.”

Ms. Patterson was back in St. Bart’s on Thursday night, with the same instrumentalists as before: the Orchestra of St. Luke’s, conducted by Ms. Greer. This time, however, the singer had the stage effectively to herself. The program was called “Humanity and Transcendence: Solo Works for Alto.”

On offer were three Bach cantatas, and three of his best. Of course, when you look at the 200 cantatas that have come down to us, you find that they are pretty much all his “best.” And what an apt — indeed, perfect — title: “Humanity and Transcendence.” (By the way, Ms. Greer writes exquisite and enlightening program notes.)

The first cantata was “Ich habe genung,” BWV 82, maybe the most beloved cantata of them all. In the middle of this work lies “Schlummert ein,” the lullaby. Is it the most sublime lullaby ever penned? I’d say.

And Ms. Patterson sang it beautifully, richly, soulfully. She also sang it without pretentiousness, without any fuss. She simply let it out. Moreover, her technique seems utterly natural, although that “naturalness” may come from loads of hard work.

Unfortunately, you could not really hear Ms. Patterson’s low notes, even over the dinky orchestra behind her. (The St. Luke’s players numbered about 12 on Thursday night.) In my experience, you can never quite hear the low notes in “Schlummert ein,” except in studio recordings.

The last aria of BWV 82 is “Ich freue mich auf meinen Tod,” and Ms. Patterson brought a little fire to it. She was admirably direct. But her sound was slightly hooded, and she might do well to open it a bit, while retaining her richness and soulfulness.

Next of our cantatas was “Gott soll allein mein Herze haben,” BWV 169. Ms. Patterson sang its arias with wonderful resoluteness, a resoluteness that contained much beauty. She expressed feeling, but was never wrongly emotional. And her singing was very, very even. She contributed a bit of an alto’s throb, when it was appropriate, and her intonation was always spot-on — amazing.

Furthermore, she sang as though she believed what she was singing. This is crucial in music of this type. I have no idea what Ms. Patterson’s beliefs are, but the point is: You have to sing as though you believe. A word about recitatives: These can be harder than the arias, but Ms. Patterson handled them with complete naturalness. She was careful, I would say, without being cautious. She was precise, but not self-consciously so. She simply talked/sang. Her mastery was as clear in the recitatives as in the arias.

BWV 169 closes with a chorale, and Ms. Patterson was joined by three other singers for this — a soprano, a tenor, and a bass. The chorale, “Du süsse Liebe,” is ultrabrief, but it leaves an impression. And from Ms. Patterson et al. it was lovely, full, and blooming.

The third and last cantata was “Vergnügte Ruh, beliebte Seelenlust,” BWV 170. Do you know Janet Baker’s recording of this piece (with Neville Marriner and the Academy of St. Martin-in-the-Fields)? If not, please stop reading this review this instant and find it.

But Brenda Patterson did it justice, too. She was good in every particular, but the particulars were essentially unnoticeable. What I mean is, the particulars were beneath notice, because a) they could be taken for granted, and b) the whole was so good. Always, there was vocal focus, and an intelligence about text, and a mental certainty.

Ms. Patterson put the right amount of pain in the middle aria, “Wie jammern mich doch die verkehrten Herzen.” And she rendered the final aria, “Mir ekelt mehr zu leben,” with sprightly conviction.

We are reminded that not all superb singers appear on leading opera stages, or have Deutsche Grammophon contracts. We are reminded that not all outstanding musicians are rich and famous.