The National Symphony String Quartet chose well in framing Ulf Grahn's new quartet against a background of quartets by Haydn and Hindemith at the Corcoran Gallery last night.

Both that particular Haydn, the Op. 20, No. 2, and the Hindemith are structurally clear. Their architecture and design are their most important features, and the ensemble did everything possible to emphasize these aspects of the music.

Grah's Quartet No. 2, dedicated to the NSO Quartet and played for the first time in this concert, is of a very different nature. Working within a highly chromatic but essentially tonal context, Grahn focuses interest on the rich varieties of textures and of sonorities that he manipulates so thoroughly.

Out of an eerie void of high harmonics, the presence of lyrical solo lines becomes felt, and as these move to the foregound, they are projected over a background of tremolo and trills.

The 12-minute piece is in one movement of two main sections. The harmonics and tremolo are a unifying force tying together the more lyrical first section and the squarer, more concise second.

This is attractive and accessible music, nicely put together and constantly interesting.

Perhaps, another time, the NSO Quartet might consider playing it twice on the program so that its intricacies have a fighting chance of being understood.

After a shaky start in the Haydn, which sounded under-rehearsed, the ensemble settled in to smooth and determined music-making.