Not long into his concert on Wednesday night, Thomas Quasthoff had a message for the audience: “I’ve been on Carnegie Hall’s stage many, many times, but I’ve never been more nervous, because it’s your music, your language. If there is something wrong, be nice.”

What was this famed German bass-baritone doing? He was singing a program called “An American Songbook,” offering jazz arrangements of standards (and a few less standard songs). The program mirrored his new CD, “The Jazz Album: Watch What Happens,” reviewed in these pages last week.

He was also finishing up his “Perspectives” series at Carnegie Hall. In these series, musicians are supposed to show their various sides and abilities — Mr. Quasthoff has certainly done that.

It has long been obvious that he loves American music, particularly spirituals and jazz. And he takes pride in singing jazz like a bona fide jazz singer, instead of a classical singer doing “crossover.” I myself would not knock crossover — but Mr. Quasthoff has a point. He does, indeed, sound like a jazz singer, with the right inflections and instincts. But he is also endowed with an extraordinary voice and technique.

On Wednesday night, he used a microphone, jazz style, pop style. It was slightly strange to hear this famous voice altered by a microphone. Also, Mr. Quasthoff read the music, or the lyrics, or both — and he did so fairly intensely. If a microphone was typical, this was not.

Nonetheless, Mr. Quasthoff sang his songs, and sang them successfully, for the most part. At one point, he dispensed with his combo — a five-man band — and simply scatted. Scatted his brains out. It is amazing what can come from the human throat, at least Mr. Quasthoff’s.

You couldn’t like the way he did every song, and I have my gripes: “The Lady Is a Tramp” was weirdly fast — rushed through — and so was “Accentuate the Positive.” These songs should have been more savored, enjoyed. But they were not unenjoyable altogether. By the way, growling through “Accentuate,” Mr. Quasthoff sounded a bit like Satchmo.

He speaks very natural American English, does Mr. Quasthoff, but, still, a few words were funny, and endearingly so: “Bust” came out rather German; we heard “Edizon” instead of Edison; and he pronounced “California” like … well, like the governor of that state.

I should also note that Mr. Quasthoff is a highly personable guy — mordant, too. After he announced “The Lady Is a Tramp,” he added, “Of course.” When he came back after intermission, he said, “Nobody left — wow.” (Maybe he was not feeling his most confident?) Later, he said “three” when he really meant “four.” He quipped, “Counting was never my thing — that’s why I became a singer.” All musicians in the hall must have gotten a special kick out of that.

The featured player in the combo was Till Brönner, a trumpeter. His bio tells us that he “has sold more records than any other German jazz musician.” That may be so, but, as Bill Buckley once asked in a different context, “Isn’t that on the order of celebrating the tallest building in Wichita, Kansas?” In any case, Mr. Brönner is a capable player. And so is the percussionist Peter Erskine — he provided the combo some spine and what you might even call leadership.

At their best, the five players were smooth and engaging; at their worst, they were dull but harmless.

For Mr. Quasthoff, the weakest moment came with “Danny Boy,” accompanied by guitar. (Did you know that Schwarzkopf sang “Danny Boy”? She used it as an encore for her British Isles audiences.) I’m afraid that Mr. Quasthoff sang it with unappealing distortion, and he also sang it flat. You must go and I must bide, but Mr. Quasthoff must go and get the hang of “Danny Boy.”

Much better was “You and I” (Stevie Wonder), which Mr. Quasthoff belted, but in a rounded way — rounded belting can be a treat to hear. And “Smile” had its effect. Before singing it, Mr. Quasthoff said that this was his life motto: “Smile” (no matter what).

Incidentally, isn’t it extraordinary that Charlie Chaplin composed “Smile”? Talk about multiple talents.

Neither you nor I nor anyone else will want Mr. Quasthoff to give up “Die schöne Müllerin.” But almost 50 years ago, the awesome soprano Eileen Farrell declared, “I got a right to sing the blues,” and Mr. Quasthoff has a right to sing his jazz. In doing so, he gives much pleasure, to himself and us.