NO ONE WHO IS is seriously involved with recordings could think of getting along without the Schwann catalogue; it is one of the few things around which may honestly be called indispensable, even if every individual user may not agree with all the publisher's decisions on what to include and how to list it. The latest innovation in "Schwann 1," the regular monthly edition, is the addition of an "Audiophile" section in which digital, direct-to-disc, and other "high-technology" recordings are listed. This is certainly handy for those who are after sonic showpieces to show off their rigs, but others ought not to infer (as they are likely to do) that the "Audiophile" category contains only "demonstration" discs and nothing of musical value. The Denon and Telarc items listed therein, to cite only two conspicuous labels, are assuredly to be considered on musical grounds as well as sonic ones.

By way of pointed illustration are two very striking new releases from Denon-one orchestral, the other of chamber music. The former is a performance of Tchaikovsky's Fourth Symphony by the [East] Berlin Symphony Orchestra under Kurt Sanderling (OX-7137-ND). Sanderling, it will be remembered, was for some years co-conductor (with Evgeny Mravinsky) of the Leningrad Philharmonic, and it was he who conducted the Fourth in that orchestra's first Deutsche Grammophon recordings of the last three Tchaikovsky symphonies, released here on on American Decca in the mid-'50s. Anyone who is familiar with that recording will know what to expect, and will not be disappointed here.

Sanderling's Tchaikovsky is filled with an unselfconscious dignity that never gets in the way of the music's dramatic flow but keeps the musical and emotional elements in proper balance. There is no trace of self-indulgence or whim in his approach, no hotting-up, just great respect for the score and for Tchaikovsky's own good judgment. Thus the long first movement comes off with a fine sense of architectonic unity, the piquancy of the famous pizzicato scherzo is realized in full, and the finale exudes real fire without breathlessness or empty rattling. It is only in the big climax of the slow movement that Sanderling's approach may strike some as a bit too understated; the first half of that movement, though, is sheer poetry.

It is, admittedly, the sonic quality of this disc that makes it a contender with the recordings of this work under Szell, Abbado and Karajan, and in this respect what Denon has achieved with its PCM digital process (in coproduction with the East German firm, VEB Deutsche Schallplatten) is the most honest likeness of a live orchestra to be heard among all recordings of the Tchaikovsky Fourth to date. There is no artificial spotlighting of effects, no gratuitous boosting of brass or percussion outbursts-only superbly balanced, utterly realistic sound and, by no means incidentally, absolutely silent surfaces.

The annotative insert (in Japanese only, except for the brief blurd on Sanderling) lists Denon numbers of Sanderling's recordings of the four Brahms symphonies with the Dresden State Orchestra. These cannot be digital recordings, but they would be most welcome here, to judge from the exceptionally enthusiastic reviews they received in England and Germany a few years ago.

In the meantime, Denon continues its more conspicuous chamber music activity with the third and final installment in its series of all the Dvorak piano trios as played by the Suk Trio. OX-7134ND is devoted to the last of the trios, the famous Dumky in F minor, Op. 90, and the performance is as idiomatic and persuasive as one could imagine.Neither side is very generously filled in respect to playing time, but there are other recordings of the Dumky Trio which occupy a full disc. This one does include an engaging little bonus in the form of a poignant (and virtually unkown) Elegy for piano trio by Josef Suk, grandfather of the violinist of the same name and son-in-law of Dvorak, who leads the performing ensemble.