The Takacs String Quartet is good enough to inspire heretical thoughts, not about its playing, but about the music it plays. On Monday night, the almost quarter-century-old quartet brought music of Dvorak, Bright Sheng and Beethoven to the Freer Gallery's Meyer Auditorium.

Dvorak: so few great works, so many miles of mediocrity; Sheng: the real thing among today's young composers; and Beethoven: Why does every 19th-century quartet written after Beethoven seem anticlimactic?

The half-Hungarian, half-English quartet has been a regular at the Freer for years. The ensemble's appearances, especially last year's daunting traversal of all six Bartok string quartets, are a highlight of the local chamber music scene. The quartet also has special appeal as a kind of phoenix of chamber music groups. In 1993 it lost two of its original members and the quartet's early profile as a stellar, ferocious young Hungarian virtuoso ensemble was in jeopardy. The multitudes of prestigious awards the Takacs won in its youth, and the phenomenal discography it had built on the London/Decca label, were about to turn from resume to legacy.

The quartet came back with two replacements, who have integrated themselves into the quartet nicely. The Takacs is again one of the great quartets of the world.

On Monday the group began with Dvorak, the quartet Op. 51, No. 10. Its second movement is a dumka, a word that sounds like an affectionate Czech insult but, in fact, signifies a folk ballad form that alternates extremes of melancholy and feverish ecstasy. Dvorak produced works of terrifying beauty--especially the Piano Trio, Op. 90--in this simple but rich form; the string quartet heard Monday, however, is not one of them.

Dvorak's mediocrity sounded tragic on Monday night. One hears a few melodic ideas, a few harmonic bits of color, and then acres of repetitive thematic development. He tries too hard to be Brahms. The Takacs had fun with it, but it was definitely music to be dispensed with quickly.

The String Quartet No. 3 of Sheng (a Shanghai-born composer who turned 44 on the night of the concert) brought the Takacs back to familiar territory. It performed his Third Quartet in the same series a few years back, and it's championed the composer in part because his best music has the athletic directness of Bartok. Sheng's quartet is a one-movement fantasy, with the occasional reference to time the composer spent in Tibet (most notably the conclusion, in which the cello intones a single slow, gravelly note like the chanting of Buddhist monks). More important than this reference, and the occasional modal thematic snatch, is the composer's sense of drama and intuition. He ends his quartet with a luminous, prayerlike elegy, reminiscent of Beethoven's String Quartet Op. 132, in which the third movement, known as the "Heiliger Dankgesang," descends like a Messiah on a troubled mind.

All of which made the quartet's concluding work, Beethoven's Op. 132, both an intelligent and emotionally welcome capstone. The Takacs players took a flexible and amiable tempo in the "Heiliger Dankgesang," a dignified walking pace rather than a more risky extension to a more static, reverent suspension of pulse. It worked, especially in the concluding transcendent harmonies and in relation to the surrounding music. The final movement was brisk and backslapping, like a fast curtain on a sad scene.