A composer must be a weaver; his creations, like cloth, have warp and woof, and some degree of lightness or heaviness, thickness or thinness, to say nothing of color. Last evening's Paine Hall concert by the Cambridge Quartet and assisting artists offered a particularly fine chance to study musical texture, especially since the musicians included some of the College's best.

The opening work, Mozart's Quartet in C-major, K.465 (1785), with its famous pessimistic introduction, contains some daring harmony which several of the composer's contemporaries felt obliged to "correct." But just as important is the extraordinarily limpid texture and intense purity that extend from first note to last.

A Fugue for String Quartet (1955) by Victor Yellin, teaching fellow in Music, received its first performance. It is an avowedly academic exercise in a traditional style as taught to Paris Conservatory students. A suave theme forms the basis of a strict contrapuntal texture that Yellin handled competently. Some of the harmonies, however, are questionable, and the piece ends a bit too abruptly.

Beethoven's 'Archduke' Trio (1811), for violin, 'cello and piano, was the last great achievement of his middle period. It is almost symphonic in concept, and at times bursts the limits of the medium, as Beethoven was to do still more in his last period with such works as the Hammerklavier Sonata, the Grosse Fuge and the Missa Solemnis. The Trio posed for the composer a problem of balance between piano and strings. Beethoven's keyboard part is full of massive chords and rich arpeggios; to help compensate for this the string parts contain many double notes. The result is a work of far richer texture and sonority than the Mozart or Yellin.

The difficult medium of two violins, two violas and two 'cellos has tempted few composers. Brahms adopted it twice and contributed the two finest examples of string sextet, of which the first in B-flat (1860) was performed last night. Brahms achieved a perfect balance between Romanticism and Classicism; the stuff of his music is Romantic, but its manipulation and design are Classical. This warm and glowing sextet is a veritable textbook of almost endless varieties of string texture. For example, the Andante often uses the violas and 'cellos as a dark quartet; the Scherzo utilizes the six instruments in three pairs; and the Finale exploits the colors of a high and a low trio. All six instruments together produce a sumptuous texture that is unique.

The Mozart and Beethoven are so well known as to make inevitable a comparison, with professional standards. The musicians in the Mozart were Edward Filmanowicz and Ronald Hathaway, violins; Frederick Shoup, viola; and Charles Forbes, 'cello. The performance understandably lacked the polish ideally desired; the minuet movement was rather ragged and the first violin had some intentional difficulties. But the Beethoven performance was better than many I have heard from alleged superiors. Robert Freeman handled the exacting piano part with total ease, and Forbes displayed a consistently smooth tone and sure technique.

Linda Schein, viola, and Stephen McGhee, 'cello, joined the Quartet for the Brahms, which made fascinating listening indeed, although one of the violas was too weak in the opening movement. It was the chance to hear this rarity for which we should be most grateful.