Most ensembles that play together for long enough develop a personal style. The Prague String Quartet is no exception. Their style is characterized by a mellow, warm sound, breadth of line and no great concern for detailed precision.

All of this produced a very nice and convincing performance of the Dvorak A Flat Major quartet at the Library of Congress last night. This piece is Dvorak at his most ethnic. Dances and folk-like tunes weave their way about passages loaded with romantic passion, and the ability to dig in and emote is almost a performance prerequisite.

Jan Tausinger's Quartet No. 3, written in 1971, was of some interest. Two of the movements are labeled "aleatoric," which means that the composer has intended that some elements are to occur by chance. Nevertheless, the piece seemed not to have any discernible aleatoric elements at all. After an initial movement that seemed more an experiment with sounds and techniques than a structure, the piece settled into two rather nice movements, one lyrical and the other a fine pattern of rhythms and textures.

The concert opened with a performance of the Haydn Quartet Op. 76, No. 4, that was lacking in many of the elegant niceties of ensemble that make Haydn such fun.