The Kontarsky brothers, individually, together and in consort with such associates as their third brother, Bernhard (a conductor), cellist Siegried Palm, flutists Hans-Martin Linde and Severino Gazzelloni and conductors Pierre Boulez and Karl Boehm, are amazing.

Alfons and Aloys Kontarsky have been exploring familiar and unfamiliar music by composers ranging from Bach and Mozart to Penderecki and Stockhausen - and doing well by all of it.

The wonder is not the broad repertoire itself, which many lesser musicians might duplicate or surpass, but the consistently high level of authority, enthusiasm and communicativeness they bring to everything they undertake, whether it be the ingratiating four-hand works of Schubert or a new piece written for them by Boulez.

Ten years ago it was Aloys whose gastronomic activities during the period in which he recorded Stockhausen's "Klavierstuecke" were chronicled in detail by the composer in place of notes on the music itself. More recently Alfons recorded Schubert's Arpeggione Sonta with Klaus Storck playing a real arpeggione (Archive 2533 175), and Alfons and Aloys teamed up for a fine disc of Mozart's major works for two pianists (Oryx 3C-322) and a sensational two-record set of everthing Debussy and Ravel wrote for both piano duet and two pianos (Deutsche Grammophon 2707 072). Now, again for DG, these genial brothers have given us what is by all odds the most engaging recording yet of all 21 of Brahms's Hungarian Dance in the original version for piano, four hands (2530 710, also on cassette 3300 710).

Those who have enjoyed the recent Connoisseur Society disc of the Brahms dance, played by Michel Beroff and Jean-Philippe Collard (CSQ-2083), will not want to throw it away, but they may find the new Kontarsky package a strong argument for having alternate versions. The differences between the two sets of performances are conspicuous. In general, the two young Frenchmen take a more straightforward approach, indulging in little rubato or tempo variation, while the Kontarskys present a more highly characterized reading of nearly every one of the dances.

In one case only, the slow section of No. 3 in F> some listeners may feel the Kontarskys overdo their staging, but after a few hearings the "straight" performances is likely to seem bland. Even with their somewhat slower pacing in most of the dances, the Kontarsky exude the greater sense of liefe and sparkie, making us feel these slight but charming pieces are the most fun anyone could imagine, either as listener or as performer. The stunning sonic frame DG has provided is itsef a major factor in the record's almost extravagant yield of pleasure. The sound is exactly that of a real live piano played by real live Kontarskys.

Another unusually interesting piano recording from the same company, but this time with only one performer at the keyboard almost all the way, is the collection of Villa-Lobos works played by ROberto Szidon (DG 2530 634, cassette 3300 634). Szidon is the third young Brazilian pianist to offer such a package in the last year of two, his predecessors being Nelson Freire (Telefunken SAT-22547) and Cristina Ortiz (Angel S-37110). Both Freire and Szidon include the marvelous "Rudepoema," Freire emphasizing the work's massive power while Szidon brings out its hardly obvious lyrical element - though neither pianist really neglects any facet of the work. Both are beautifully recorded.

The other major offering on Freire's disc is the first suite from "O Prolo de bebe" ("The Baby's Family (of Dolls)." Szidon gives us the far less familiar "Carnaval das Criancas" ("Children's Carnival"), with Richard Metzler joining in for the final, four-hand number, plus the "Suite Floral" and four shorther works - "A Lenda do Caboclo, A Fiandeira, Saudadles das Selvas brasileiras" and "New York Skyline." Since the "Prolo de bebe" suite is on Ortiz's Angel disc (which includes some pieces by other Brazilian composers as well as more by Villa-Lobos), the practical purchase would seem to be that plus the new Szidon, to avoid duplication and enjoy the greatest variety of repertoire. If it were to come down to a single disc, though, I would go with Freire's, for he is just that much more persuasive than either of his two splendid compatriots.