ANTON ARENSKY (1861-1906) is one of those minor Russian composers remembered more now as pedagogues, activists and continuators of a great tradition than for their own works. Rachmaninoff and Scriabin were among Arensky's pupils. His own teacher was Rimsky-Korsakov, and he received meaningful encouragement from Tchaikovsky, whom he memorialized in a string quartet whose slow movement, a set of variations on one of Tchaikovsky's songs, became a string orchestra staple.

Beyond the Variations, Arensky composed a charming miniature violin concerto, which is available on records now, and some suites for two pianos, the first of which contains a waltz made famous by Harold Bauer and Ossip Gabrilowitsch. Heifetz, who used to perform the waltz section of the concerto as an encore piece, recorded the Piano Trio in D minor, Op. 32, with Piatigorsky and Pennario. Now the Trio -- which, after the Variations, is the Arensky work we are most likely to hear -- has been newly recorded by the Eastman Trio in its projected cycle of Russian trios.

To my ear, the Eastman performance (Turnabout TVC 37016; cassette CT-7016) is the most persuasive account of this work yet offered on records. It does not sound as if the performers learned it just in time for the recording session, but as if they had lived with it a long time and developed real affection for it. As in most of Arensky's music, there is a nostalgic, fairy-tale aura to this work; the third movement is an Elegy, which demonstrates most eloquently both the composer's capacity for expressiveness and his unfailing tastefulness.

On the other side of the disc are the piano-violin-cello version of Glinka's somewhat better known "Trio pathetique" (originally for piano, clarinet and bassoon) and the Scherzo from a Trio in C by Rimsky-Korsakov, an ingratiating if hardly consequential little discovery. These, too, are presented with utter conviction and a great deal of unself-conscious polish. A most appealing issue on all counts.

In a two-disc set on the same label (Turnabout 2-TVC 37015), the Reger Quartet of Berlin performs some still less familiar Russian chamber music--the pieces composed by Rimsky-Korsakov, Glazunov, Borodin, Liadov and some lesser known figures for the Friday musicales at the St. Petersburg home of the music publisher Mitrofan Belayev. These gatherings were known as "Les Vendredis," French for "the Fridays," and under that heading an appreciable quantity of short pieces was created. Belayev himself occasionally took part in the performances as violist, and Borodin sometimes played the cello when a second was called for.

Recorded here are a scherzo by Borodin, which that composer used in his unfinished Third Symphony (orchestrated by Glazunov), an unextended Allegro by Rimsky-Korsakov, several tiny pieces in classical forms (sarabande, courante, etc.) by Glazunov and Liadov, and some similarly diverting ones by the virtually unknown Nikolai Artzibushev, Maximilien d'Osten-Sacken, Alexander Kopylov, Felix Blumenfeld, Jasep Wihtol and Nikolai Sokolov. Possibly the best-known product of these musical Fridays, the polka titled "Les Vendredis," was composed jointly by Glazunov, Liadov and Sokolov; it is, of course, included here.

Since the material from "Les Vendredis" takes up only three sides, the fourth is devoted to a work by Glazunov, his five "Novellettes" for string quartet, Op. 15. This sequence begins with an "Alla spagnuola" and concludes with an "All' ungherese"; between these two "national" pieces are an "Orientale," a lissome Valse, and, as centerpiece, the "Interludium in modo antico," which used to enjoy a certain prominence on its own in string quartet programs.

While there is nothing approaching "great music" or even "important music" here, this is a refreshing and, to a certain degree, illuminating addition to our knowledge of Russian music and some of the figures who created and sustained it. The performances throughout the set are as sympathetic as can be, the recorded sound is first-rate, and there is a most interesting set of notes on the music and its original setting by Malcolm Hamrick Brown of the Indiana University School of Music.