Cellist Luis Leguia studied with Zolta'n Koda'ly, and when he plays Kodaly's daunting Sonata, Op. 8, for unaccompanied cello, we may assume that he is following the composer's directions. His performance last night at the Library of Congress had an air of authority and solidity about it that supported such an assumption.

The sonata is a brilliant, rambling, wildly rhapsodic piece, full of soulful Hungarian melodies and peasant dance rhythms. The cello often serves simultaneously as a wordless singer (in a melody played by the bow) and its own guitarlike accompaniment (in notes or chords plucked by the left hand). It is moody music, ranging mercurially from depression to ecstasy; spectacular music, forcing the cellist to display almost every known technical resource of his instrument; exciting music--particularly in a live performance, where the sight of the cellist sitting alone on the stage and producing all that variety of sound enhances its effect.

Leguia played it almost flawlessly. If there was any problem, it was the matter-of-fact ease of his performance, the feeling that everything was completely under control, which prevented tension from building to its maximum. But the music itself has tension enough, and it was easily the climax of a varied and fascinating program by Leguia and pianist Alan Mandel. The other pieces ranged from Anton Webern's brief, enigmatic Cello Sonata--a complete and complex statement that spanned only a few minutes--to Edward MacDowell's Piano Sonata No. 4 in E minor ("Keltic"), in which Mandel had his finest moments. The "Keltic" is a heart-on-the-sleeve piece of unabashed romanticism, fervently emotional, wildly virtuosic. It's a fine argument for the theory that music can be enjoyable even if it has no originality at all.

The program closed with Charles Martin Leoffler's Poe me for cello and piano, a pleasantly rhapsodic piece that runs through a variety of styles (sometimes with two styles running simultaneously in the cello and piano) but manages to achieve a unified effect nonetheless. Remarkably, these four works were composed within 16 years of one another at the beginning of the present century, though their styles ranged from mid-19th century in MacDowell to mid-20th in Webern. All were played with sensitive awareness of their special stylistic qualities, and in the duet pieces the cellist and pianist were well coordinated.

It may have been a mistake to open the program with Beethoven's Sonata in A, Op. 69. This is probably the greatest work in the cello-and-piano repertoire, and one that normally comes at the climax of a program, after the audience and players have warmed up with lesser material. The performance was a good one, but it might have been even better a bit later in the evening.