The Norwegian pianist Leif Ove Andsnes is in the midst of what they call the Andsnes Project, at Zankel Hall (which is in Carnegie’s basement). This has the pianist programming whatever he likes, in the company of many musicians, several of whom are no doubt friends. The project began last Friday, and continued Monday night; it will conclude this Friday night.

Monday night’s program, like the others, was wildly eclectic, beginning with a sonatina for clarinet and piano by Matthias Ronnefeld, an Austrian-Danish composer who died in 1986 at the age of 27. The sonatina is in three movements, each designated by a metronome marking (and nothing else). The piece is generally peppy and nervous, like so many written for the clarinet. It riffs around, throwing up fragments – little ideas and exclamations. It seems a piece excited about composition. Occasionally, the piano’s strings are strummed, plucked, or otherwise accosted. The middle movement is a small song, bleak and touching. And the last movement is full of stunts: A metronome, placed on a table, ticks away; the clarinetist blows into his instrument, without benefit of mouthpiece; he sings and groans. It may be that there’s a bit of parody going on here.

Anyway, the audience loved it. A piece like this is beyond criticism. Who dares be a square?

The performers were Martin Frost, clarinet, and Havard Gimse, piano. (Mr. Andsnes would appear later.) That piano part is none too easy, and Mr. Gimse handled it with aplomb. Mr. Frost is obviously a skillful player, and he showed some fine colors on his instrument. As he played, he did a good deal of posing, or acting. Is this really necessary to “sell” music, or for any other purpose? Then again, Ronnefeld’s piece lends itself to a little theatricality.

The concert moved on to eight of Dvoryak’s Moravian Duets, for soprano and mezzo-soprano (accompanied by piano). It was good to hear these wonderful numbers, so seldom performed. Elisabeth Schwarzkopf and Irmgard Seefried made a fairly well-known recording of the duets, still available from EMI. They sang in German, as was the custom. Only recently have singers – non-Czech ones – undertaken the native language. Mr. Andsnes’s singers were fellow Norwegians, Ann-Helen Moen, soprano, and Randi Stene, mezzo-soprano. Each has an attractive, darkish voice, and they performed winningly. They were in sympathy with each other, and with the music. Along the way, there were technical falterings – particularly from Ms. Stene – but nothing serious.

Mr. Andsnes was at the piano, and he played in his usual clear, straightforward manner. Here is a man to give dignity, even stringency, to any music. His trilling in “Fly, Sweet Songster” – about a bird, of course – was highly dignified. Mr. Andsnes must be the least la-de-da pianist alive.

And then the Polish mezzo Edyta Kulczak joined those singers, and that pianist, for Janacek y ‘s “Rikadla,” a set of brief, characterful nursery rhymes. Mr. Frost, the clarinetist, joined them too. This makes a nice correlation of forces – and all involved seemed to be enjoying themselves, thoroughly. Mr. Frost contributed spirited, musical, and accurate licks. And the group was led by the forceful, tasteful musicianship of Mr. Andsnes.

The second half of the program saw a return to Ronnefeld’s music: We heard his “Grodek,” for soprano, mezzo-soprano, and instrumental ensemble. (Daniel Druckman, from the New York Philharmonic, was percussionist.) Set to a text of Georg Trakl, a World War I poet, this is a jarring piece, with yelps and other outbursts, manfully dealt with by

Randi Stene, in particular. Christian Eggen conducted, and did so with passion and focus.

How about some Bach? Mr. Andsnes came out for the Keyboard Concerto No. 5 in F minor, BWV 1056. Among his companions was at least one big gun, the violinist Alexander Kerr, concertmaster of the Royal Concertgebouw Orchestra, in Amsterdam. It’s nice to have friends in high places. As always, Mr. Andsnes played straightforwardly and cleanly, and Bach’s outer movements were superb. They were models for any pianist, or for anyone else. And yet, the slow movement – that wondrous thing – could have used more feeling. A little tenderness, a little give. Mr. Andsnes was cold and mechanical here. He might have been typing. Alternatively, one might have been listening to that metronome, from Ronnefeld’s sonatina. No one’s asking for a swoonfest, but really …

This extraordinary concert ended with a Gyorgy Kurtag piece, “… quasi una fantasia …,” for piano and chamber orchestra, including a ton of percussion. These players were spread throughout Zankel Hall, with only Mr. Andsnes and a few of his mates onstage. (Mr. Eggen conducted facing the audience, and the majority of his players.) The piece begins with a slow, delicate trip down the C-major scale, and proceeds in surprising ways. This is a clever piece, from a clever composer, and Mr. Andsnes and his friends made a strong case for it.

On Friday night, they will play some more Kurtag, and some Schumann. If you’re there, you won’t be square, that’s for sure.

The Andsnes Project will perform again May 13 (57th Street and Seventh Avenue, 212-247-7800).