Special to the Eagle

WILLIAMSTOWN -- Any time you see a concert announcement for two violins, two violas and cello, you can be pretty sure Mozart and Brahms will be on the program. There must be other works for that combination, but none are in a league with Mozart's four mature string quintets and Brahms' pair.

Sure enough, the Clark Art Institute's performing ensemble came to the museum Sunday afternoon bearing Mozart's C Major (K. 515) and Brahms' G Major (Opus 111). But surprise: A short Eastern European work from the 1990s introduced each classic.

A bit of cheating was involved. Neither recent work used the full complement of strings. But each offered variety - if variety can be said to be the point in minimalism.

The Performing Artists in Residence at the Clark (to give them their full name) are a group of friends headed by cellist Edward Arron and his wife, pianist Jeewon Park. Arron's partners for this visit were violinists Jennifer Frautschi and Tessa Lark, and violists Che-Hung Chen and Max Mandel.

As in the past, the ensemble proved dynamic and alert to a generous range of expressive possibilities in the music. This was a splendidly played, invigorating program. It mattered little that the newer pieces seemed of minor interest and the Brahms performance sometimes went over the top.

The Estonian Arvo Pärt's "Summa," for violin, two violas and cello, proved to be one of his mystical pieces evoking medieval chant. A repeating figure over slowly moving chords finally came to suggest a dirge in a cathedral.

Giya Kancheli's "Rag-Gidon-Time," for violin, viola and cello, was a kind of in-joke. The Georgian composer, now living in Belgium, wrote the piece for (did you guess?) violinist Gidon Kremer. Fragments of music suggested hidden music beneath (which probably doesn't exist).

The Mozart performance was clear-textured yet sensuous in its mix of lyrical warmth amid vigor of attack. Amazing to think that Mozart could be so sunny and outgoing in this late work, yet plumb tragic depths in its companion piece, the G minor Quintet.

A high point: in the first movement, the exchanges between the lyrical first violin and the gruff cello, the two of them then switching roles, talking back to each other. Serenity marked the inner movements.

Brahms poses a puzzle for players in the opening and closing movements of his Opus 111, also a late work. He asks for fast but qualifies the marking with "non troppo" -- not too fast. In the first movement, he also enjoins "con brio" -- with spirit.

The Clark players took him at his word about fast but downplayed the qualifier. The two movements plunged ahead, supercharged. Impressive show, but the note of regret and renunciation, always somewhere below the surface in Brahms, emerged only in the slower movements.