IS THERE, another pianist today who plays Chopin more beautifully than Emanuel Ax? With his first recorded Chopin collection, five years ago, it was abundantly evident that the young Polish-born pianist is a poet, with Chopin in his blood as well as in his fingers; everything he has done since then has only deepened that impression.

That extraordinary balance of enthusiasm, warmth of heart and unfailing taste that marks Ax's musicianship is the sort of thing Rubinstein, too, always gave us in his Chopin, but Ax is no mere chip off the Rubinstein block. His playing is as gladdening and revivifying as Rubinstein's because it is fully as distinctive in its way.

Ax's new recording of the Chopin E minor Concerto with Ormandy and the Philadelphia Orchestra is even more succesful than the same team's earlier one of the F minor. The new disc (RCA ATC1-4097) is digitally recorded, amd impeccably pressed by Teldec in Hamburg, but it is not, of course, the sonic considerations that make it so special. It is, rather, that "extraordinary balance" cited above, the absorption, the enthrallment, the passion, the subtlety -- all gloriously amplified by the total integration of the sound and orchestral elements in the performance. In short, here is this year's concerto record, on the same exalted level as last year's of the Beethoven C major with Michelangeli and Giulini.

Deutsche Grammophon, which gave us that Beethoven recording, has just brought out the first recording to be issued in this country of Carl Nielsen's early (1888) String Quintet in G major, played by the eponymous Carl Nielsen String Quartet with violist Borge Mortenson and paired with two of Nielsen's much later works for unaccompanied violin -- the Praeludium and Presto, Op. 52, and Praeludium and Variations, Op. 48 -- played by the quartet's leader, Peder Elbaek (2531.344).

Nielsen was only 23 when he composed the quintet. Not surprisingly, it shows a certain indebtedness to his teacher Niels Gade, and to his mentor, Mendelssohn, but Nielsen's own character is already taking shape here and is discernible without straining. In the two later works, of course (both from the 1920s), it is dominant and quite unmistakable. These are sterner stuff, thrusting, craggy, exploratory, alive with originality and imaginativeness. The performances have great sweep and conviction, and the recording is first-rate.

The most beloved of all quintets, Schubert's "Trout" Quintet in A major, for piano, string trio and double bass, is represented in two new recordings, both apparently taped in Munich. On Eurodisc 25567.KK, the pianist is a musician more familiar to most of us as a conductor, Wolfgang Sawallisch. His companions are three members of the Endres Quartet and the double bassist Walter Goetz. According to the liner information, Sawallisch performs chamber music with these musicians frequently, and three of them are principals in the orchestra of the Bavarian State Opera, of which he is music director. The performance does sound as if these men get together often enough to know each other and share a genuine mutuality of approach. They sound extremely comfortable with each other, in a brisk and bracing account of the work that allows Schubert's warmth to come through undiluted -- and unsullied by sentimentality. It wears awfully well, and the sound (in "SQ" quadro, but happily compatible in two-channel stereo) is excellent as are the German pressings.

The other "Trout," though it is a digital recording (the first for this work, I think) with the redoubtable Sviatoslav Richter, members of the recently reconstituted Borodin Quartet and the renowned bassist George Hoertnagel (Angel DS-37846), must be reckoned one of the few disappointments in this work's sizable discography. It is a dismayingly insensitive performance -- nothing like the superb Brahms Quintet by Richter and the entire Borodin foursome of old, or Richter's various recordings of Schubert solo works -- and the recording itself is a reminder that "digital" is no guarantee of excellence.