ANDRAS SCHIFF, who is 28, and Zoltan Kocsis, who is 29 but looks half his age, are the outstanding Hungarian pianists of their generation. Both are identified with the Viennese classics in their Hungarian recordings, both are beginning to circulate in our country and each is represented on a new disc of Bartok's piano music, made outside Hungary.

On a Denon digital disc taped in Japan last June (OX-7215-ND), Schiff performs the Dance Suite, the Romanian Folk Dances, the Three Rondos on Folk Tunes and the 15 Hungarian Peasant Songs. Kocsis, on Philips 9500.876 (cassette 7300.876), plays the "Allegro barbaro," the Improvisations on Hungarian Peasant Songs, the Three Folk Songs from the Csik District, the Four Dirges (Op. 9a), the Sketches (Op. 9b) and the 15 Hungarian Peasant Songs.

Both issues are superb, musically and sonically. If I had to choose between them, in order to avoid the one duplication (the 15 Hungarian Peasant Songs, one of the longer works), I would take Kocsis, but the choice would be based strictly on repertory. The Dance Suite is something one wants in its orchestral form, and the two remaining titles on Schiff's record are things one is likely to have in various other collections, while four of the six titles in Kocsis' assortment are sure to be new to most listeners and are eminently worth discovering. In the face of musicianship on this level, though, the question of duplication is perhaps more intriguing than frustrating: I suspect many who hear both discs will feel compelled to buy both.

Lorin Maazel's new recording of Bartok's Concerto for Orchestra, with the Berlin Philharmonis (Deutsche Grammophon 2531.269, cassette 3301.269), is one of the finest things this conductor has ever done. It is an exceptionally sympathetic interpretation, in which all the inner voices and little asides are clearer than ever without in any way offsetting the feeling of spontaneity one wants in this work. Dramatic, witty where appropriate, idiomatic and brilliant.

If Maazel does not quite match the persuasiveness of a Reiner (RC AGL1-2909) or a Kubelik (DG 2530.479) in the Concerto, he does offer an enticement in the form of a second work in his package: a similarly appealing performance of the much earlier "Two Pictures," Op. 10, a title otherwise unlisted in the current Schwann.

Perhaps the most striking phonographic contribution to the Bartok centenary year so far is the new set of the six string quartets, played by the Tokyo Quartet (Deutsche Grammophon 2740.235, three discs). With the deletion of the Vegh Quartet's Telefunken recording, the field was very much open for a really outstanding "integral" account of these milestone works, and that is what the Tokyo Quartet has given us.

When this group's single LP of the Second and Sixth quartets was issued, four years ago (DG 2530.658), it was announced that it was the initial installment in a complete cycle, but none of the other four works turned up until now, in the three-disc set. I have no idea how long a period was covered in the actual recording of the six quartets, but the degree of intensity and fire maintained throughout the cycle is altogether remarkable.

Still more remarkable, perhaps is the level of sheer tonal beauty that is as conspicuous and as consistent as the passion of these performances. These two elements seldom come together in any music as they do in the Tokyo Quartet's Bartok, and these works have seldom -- either in live performance or on records -- yielded the excitement and sense of fresh discovery that they do here. The exceptionally rich, lifelike and well-focused sound is no small factor in the impact made by this set, which must be the recommended version of these works now -- and, I would think, for some time beyond the current centenary observances