For more than half a century, a certain standard in the performance of Beethoven's piano music has been identified with the name of Artur Schnabel, who was born 104 years ago last Thursday and who was once told by his piano teacher, Theodor Leschetizky: "You will never be a pianist; you are a musician." Schnabel was, in fact, both; he was a composer as well as a performer, and his compositions are admired by connoisseurs,though almost unknown to the general public.

Leschetizky's quip implied a criticism of his fellow pianists, perhaps even of himself. When Schnabel began his career, late in the past century, pianists felt free to take considerable liberties with the music they ld,10 SW,-2 SK,2 played, using it as a vehicle for the expression of their own beautiful, bruised souls and the display of their extraordinary technique.

Schnabel may be most fondly remembered, in the long run, for his often-stated conviction that some music (the late piano sonatas of Beethoven, for example) is "better than it can ever be performed." By teaching and example, he established an ideal of self-discipline and dedication to the printed score that has become the standard for later generations of pianists.

As happens so often, some of the disciples went beyond their teacher. Fidelity to the text was escalated into a kind of deadpan approach that, in extreme cases, kills the spirit by strict adherence to the letter. This was no part of Schnabel's ideal; he spent his life finding ways to reconcile fidelity to the music with expression of his own personality and ideas. But the composer's intentions, as expressed in the written score, were always foremost in a Schnabel interpretation. The best of his disciples -- Leon Fleisher, for example -- have carried on this tradition.

Since the 1930s, during a period of rapid, spectacular growth in performance techniques, Schnabel's interpretations may have been surpassed by later pianists. This is certainly true in purely technical terms, where some objective judgments are possible. Schnabel was not unduly concerned about an occasional wrong note and refused to do partial retakes of a performance to eliminate such slips of the finger (an almost universal practice in studio recordings today).

Die-hard fans treasure some of his recorded mistakes as much as his moments of deep inspiration. The mistakes are a sign that he believed in spontaneity as well as careful preparation and that, despite his high standards, he did not fall into the trap of perfectionism. He had ambivalent feelings about the recording of a performance, which he called "self-destruction through preservation."

Self-destructive or not, Schnabel's recordings have certainly preserved his art. They have been made available (and have sold not spectacularly but steadily) in each newly developed recording medium of the past half-century. Now, at the dawn of digital recording, they are beginning to appear on compact discs. Some of his solo piano recordings (notably the Beethoven sonatas) are promised for later this year. But the first to be processed into the new format are the five Beethoven Piano Concertos, recorded in London between 1932 and 1935 with Sir Malcolm Sargent conducting. These have been issued on three Arabesque compact discs (numbered Z6549 to Z6551). On Z6551, there are also two short solo piano works, the popular Andante Favori and the Polonaise in C, Op. 89, which were recorded in 1938 but have not been previously issued.

This set does not really replace the one issued by EMI in the 1960s (with deluxe packaging and superb annotations) in its "Great Recordings of the Century" series. Only the First Concerto is identical in both sets. The other four in the EMI set were recorded after World War II, not long before Schnabel's death in 1951. They embody, superbly, his later thoughts on the music, and those who have the "Great