What exactly makes a piece of music "French" can be debated at great length. However, we can agree upon two distinctively Gallic characteristics: elegance and clarity. These qualities are perhaps most visible in French chamber music, especially in works by Ernest Chausson, Maurice Ravel and Francis Poulenc, composers well-represented by two groups that are no strangers to Washington audiences: the Beaux Arts Trio and the Chamber Music Society of Lincoln Center.

The Beaux Arts Trio, fresh from its completion of Beethoven's piano trios last week at the Library of Congress, has brought together the trios of Chausson and Ravel (Philips 411 141-1 digital), a thoughtful pairing indeed. Both men's chamber music output is slender. Chausson has never received his due, a pity, since he was a link between the late Romantics and the Impressionists. A man of means who decided on a music vocation rather late in his short life (he was killed in a bicycle accident at 44), Chausson nevertheless developed his own luxuriantly melodic style, one that lent itself well to the clear-cut, cyclical structures he learned from Ce'sar Franck.

His "Piano Trio in G Minor," Op. 3, written when he was 26, fairly overflows with gorgeous themes, suave harmonies and a rigid sense of symmetry -- Chausson meticulously proportions each movement, avoiding any excess verbiage. He can be a bit foursquare, as in the second movement, "Vite," but rhythmic invention was not his strong suit. The Beaux Arts players -- pianist Menahem Pressler, violinist Isidore Cohen and cellist Bernard Greenhouse -- give the sort of vibrant, expressive performance one almost takes for granted from them.

Their latest reading of Ravel's "Piano Trio in A Minor" compares favorably with the one they recorded for Philips in 1966. At that time, Daniel Guilet occupied the violin chair. The earlier version has a warmth and immediacy missing in the recent digital release, which, contrary to the listed timings, seems much more energetic than its predecessor. In truth, their newest Ravel is more measured, though it possesses a much more pronounced rhythmic vitality. Ravel's metrical concerns are like those of a poet: He uses a swaying 8/8 (3+3+2) in the first movement, vacillates between 5/4 and 7/4 in the finale and includes skillful thematic enjambments in the "Pantoum," modeled after a Malaysian verse form adopted by Victor Hugo. The trio responds to the greatest difficulties with the greatest of ease, creating a rich ensemble sound in "Pantoum," and pulling in the reins for the sparser-textured "Passacaille." Philips' digital mastering and clean surfaces capture it all with spacious sound.

The Chamber Music Society of Lincoln Center, by contrast, has accomplished a singular feat: assembling Poulenc's complete chamber music for wind instruments and piano in a two-record set (Musicmasters MMD 20040/41 digital). This package is long overdue, for although Poulenc (1899-1963) was a minor composer, his lyric facility made him a consistently engaging one. American composer Ned Rorem in his perceptive liner essay likens Poulenc to an "inverted cuckoo" that eagerly hatched the eggs of songbirds past and present, producing offspring that miraculously shared its plumage without disguising the musical traits of their "fathers."

Rorem assigns Poulenc, whom he dearly admires, the tag of plagiarist par excellence. If one accepts a bird analogy, let it be one where Poulenc is a mockingbird that internalizes its neighbors' unique chirps, and reiterates only those it deems worthy -- but always with its own distinct inflections.

Heeding Rorem's words, one could spend hours noting the influence of Stravinsky, Ravel, Satie, Schumann, Brahms -- even Schoenberg in the "Elegie for Horn and Piano." This activity is a waste of time. Consistency and fluency were Poulenc's trademarks. The present collection, which contains nine works spanning 44 years, bears this out. His works are not arranged chronologically, because Poulenc did not so much evolve as spring, Minerva-like, into action, fully equipped to compose.

Consequently, there's no harm in the Lincoln Center group opening with his "Sextet for Wind Quintet and Piano," a lively 1930s piece these musicians brought to the Kennedy Center earlier this season. Here, as in most of Poulenc's chamber efforts, three movements (never four) suffice to make a point. Sprightly passages dart in and out among the instruments, with the French horn, dexterously played by Robert Routch, joining the merriment. It's giddy good fun, and one can practically see the composer's laugh lines deepening.

Although jocosity (misread as mere frivolity by many) dominates, Poulenc sets up some tender dialogues in his miniatures, the "Sonata for Two Clarinets" and "Sonata for Clarinet and Bassoon." Gervase de Peyer and Peter Simenauer play a game of tag in the close harmonies of the former, while the latter, with bassoonist Loren Glickman joining Peyer, alternately waxes dour and delightful. A not-so-pleasant exception is the "Elegie," in which Poulenc's clumsy 12-tone rows and grumpy French horn melodies seldom see eye to eye. He no more had a feel for serialism than did Schoenberg for New Orleans jazz.

Two of Poulenc's better-known chamber works bask in the flip side of a smile, tristesse. The "Sonata for Clarinet and Piano" and the "Sonata for Oboe and Piano" draw a fine line between touching the funnybone and the heart. Charles Wadsworth sturdily anchors both, allowing Peyer and oboist Leonard Arner respectively to strut or deliberate on their melodies.

Rorem comments on the unbending sameness of this music, adding that Poulenc "never changed his tune throughout his life." He didn't have to. The utter ease with which he composed, the undeniable "rightness" of each setting, the clever twists that could provoke laughter or sudden, fleeting pangs of sorrow (without belaboring either extreme) know few equals.

Poulenc, who did not cut a particularly dashing figure, seemed hard pressed to write music that was anything less than refined -- which is what attracts us to this quixotic, quintessential Frenchman's works again and again.