On Sunday afternoon, the Chamber Music Society of Lincoln Center featured Joan Tower, the American composer. She is CMS’s “season composer” for 2007-08. (Didn’t we used to say “composer-in-residence”?) Three of Ms. Tower’s works were heard on Sunday’s concert, which was held at the Society for Ethical Culture, CMS’s temporary home, while Alice Tully Hall is being renovated.

Two of those Tower works are for viola, alone. One, called “Wild Purple,” was written 10 years ago. The other, “Simply Purple,” was written this year. These are not to be confused with “Deep Purple” or “The Color Purple” — although there is some relation. Ms. Tower thinks of the viola’s color as purple. She has written that the “deep, resonant, and luscious timbre” of the viola “seems to embody all kinds of hues of purple.”

“Simply Purple,” as the title may suggest, uses simple compositional materials: slow scales, rocking intervals. Then a songfulness appears, imparting soul. In all, this is a little scena for viola. Ms. Tower packs a lot into four minutes.

And the companion piece of this new work, the older “Wild Purple,” is even more a scena, or monodrama. And it is, of course, wild. Ms. Tower said she had never thought of the viola this way, “so I decided to see if I could write a piece that had wild energy in it.” She succeeded.

Both pieces were written for the violist Paul Neubauer, who played them on Sunday afternoon. Chances are, they will never have a better player. Mr. Neubauer is a consummate violist, and one thing he can do is vary the width of his sound, to meet whatever the musical need is. He is a champion of a much-maligned instrument — think of those viola jokes! — and he is one of the best string players around.

Later on in the program came a Tower piano trio, written last year. This is called “Trio Cavany,” and that last word stands for California, Virginia, and New York. The organizations that commissioned the piece are in those states. How Ms. Tower pronounces the word, I don’t know.

The trio is in one movement, but you can imagine movements, or sections, within the whole. It begins bleak and ghostly — in other words, like 50,000 other pieces written in the last 20 years. But then some interesting harmonies occur, and some interesting rhythms. The music is now martial, now lyric. All of a sudden, the pianist is playing Liszt, or Busoni, or Scriabin. Sometimes the music is thick and Germanic; sometimes it is spare and rather French. Eventually, we are back to bleak and ghostly.

I award this piece a high commendation: I would like to hear it again (despite that dorky title). And it was well performed by André-Michel Schub, piano, Cho-Liang Lin, violin, and Gary Hoffman, cello. Mr. Schub, in particular, plays with remarkable self-possession.

At the beginning of the concert, Wu Han, one of the Chamber Music Society’s artistic directors, spoke to the audience. (Mercifully, she was brief.) She said that Ms. Tower had been asked, “Who are your favorite composers? What composers would you like placed among your works?” And she spoke three names: “Haydn, Beethoven, and Dvorak.” And those were the other composers on the program, represented in trios.

Beethoven wrote his Variations in E flat for Piano, Violin, and Cello at age 21. They are bursting with talent and life. Messrs. Schub, Lin, and Hoffman gave them a decent account. But the violinist, unfortunately, did not make his best sounds. Nor did he demonstrate his best intonation. And all three performers might consider whether they play Beethoven’s slow variations too slowly.

Haydn was represented by his Piano Sonata in G, Hob. XVI:40. Come again? In Haydn’s own lifetime, someone — we know not who, but not Haydn — arranged this sonata for violin, viola, and cello. In my view, this arrangement has no compelling reason to exist, and there was no great reason to program it. But there it was, adequately performed by Messrs. Lin, Neubauer, and Hoffman, despite the violinist’s ongoing problems.

The concert concluded with a long, distinguished work by Dvorak — the Piano Trio in F minor, Op. 65. What the performance lacked in technical polish, it made up for in honest musicianship. A listener could get lost in Dvorak’s music (in a positive way). This was especially true of the slow movement.

Mr. Schub played with grace, fluidity, and sense. We can see why he won those important competitions, including the Van Cliburn, moons ago. Mr. Hoffman did some beautiful, well-judged, noble playing. And Mr. Lin showed us how he acquired his reputation in the first place.

In her concert-opening remarks, Wu Han noted that Ms. Tower could not be present, as she was nursing an injury at home. But someone in the balcony was going to relay the concert by cell phone, so that the composer could hear. And that, friends, is a fine use of a phone in a concert hall!