SALZBURG, Austria — It is a privilege to sing a voice recital at the Salzburg Festival — particularly a recital of German art song. Elisabeth Schwarzkopf and Dietrich Fischer-Dieskau did it, a lot. And, last week, Christine Schäfer, the German soprano, did it. She certainly deserves the privilege.

Her program was a Schwarzkopfian one: Bach, Mahler, and Wolf. And she began with five songs of Mahler, four of them from “Des Knaben Wunderhorn.” As always, Ms. Schäfer was tasteful and intelligent. I have said before that she sings lieder almost “objectively” — without interpretation. The songs are strangely pure and unaffected.

To single out just one of these Mahler songs for praise, “Ich ging mit Lust” featured extreme delicacy and ethereality. You practically held your breath.

Ms. Schäfer did not sing effortlessly or perfectly — I mention this, because she has often done so in the past. The imperfections included some fraying up top — also some dullness, frankly. For instance, “Wer hat dies Liedlein erdacht?” could have used more character and, at the most basic level, more volume.

The pianist was Ingo Metzmacher, a German who is also a conductor. For the most part, he played naturally and unobtrusively. He was neither a potted plant nor an attention-grabber. I offer just one detail: His hesitations in “Rheinlegendchen” were exactly right.

The performers’ second set was Bach and Mahler — one Bach song, then a Mahler song, then another Bach, and so on. Obviously, some musicological point was being asserted here. But no matter: We were privileged to hear Christine Schäfer sing.

And yet her problems continued. Technically, there were various glitches — little hiccups and bumps and smudges. This was nothing serious; but it was slightly disturbing all the same. There was even bad intonation, which is very, very un-Schäfer-like.

Furthermore, you could (again) challenge her on musical grounds. For example, Mahler’s “Wo die schönen Trompeten blasen” needed more bloom — Ms. Schäfer was unnaturally dry. And “Bist du bei mir” (long attributed to Bach but apparently written by a man named Stölzel) was a disappointment. It was fast, unsavored, and cold — as though the “period” police were breathing down the singer’s neck.

Neither was Mahler’s “Urlicht” as good as it had a right to be. It did not transcend or transport. The music — some of Mahler’s most sublime — was oddly pedestrian. Part of the problem was the pianist, who was more plodding and blunt than he intended to be, I believe.

After intermission, Wolf had the stage, as the performers gave us 14 of his songs — 10 of them to texts of Mörike, the other four from “The Spanish Songbook.” Ms. Schäfer sang her first Wolf song, “Schlafendes Jesuskind,” very, very touchingly. It was important that she was not too gentle with it, not the least timid about it. She just tucked into it.

In “Die ihr schwebet,” she showed high-flying vocal artistry. “Ach, des Knaben Augen” was marked by sincerity and simplicity (two of this singer’s specialties). And “Zitronenfalter im April” was intimate and jewel-like.

Again, there were imperfections — in one song, Ms. Schäfer actually stopped phonating (i.e., making a sound). And she was sometimes too modest and self-effacing for her own good — or the music’s good. This was true of “Auf einer Wanderung,” which needed far more personality. (The common fault is that singers inject too much.)

And yet, if you wanted transcendence and transport, Ms. Schäfer came through for you — with the help of Mr. Metzmacher. “Im Frühling” was a musical and metaphysical triumph. The atmosphere in the hall was noticeably changed. Audience members were in a different realm.

The printed program ended with one of Wolf’s best, and one of Mörike’s best: “Neue Liebe,” or “New Love,” which ends, “I marvel that it should have ever seemed to me a marvel to have God Himself for my own here on earth!”

Ms. Schäfer did not have her best night. Technical problems aside, she committed dullness, which was fairly shocking to me. But I would rather hear a subpar night for her than a maximally good night for others. And that is one way you know you’re dealing with a great singer.