CBS (heretofore known as Columbia) is the latest major record company to come out with digitally recorded discs, and apparently the first of any size to bring out digitally recorded cassettes. All the items in the CBS "Mastersound" series are being issued in both formats, with a list price of $14.98 per disc or cassette.

The four discs I've heard are remakes of the respective titles by the conductors involved: Shostakovich's Fifth Smyphony, recorded live in Tokyo last summer by Leonard Bernstein and the New York Philharmonic (IM 35877): Stravinsky's "Petrushka" (1947 version) with thethe New York Philharmonic under Zubin Mehta (IM 35823); and three Strauss tone poems -- "Don Juan," "Till Eulenspiegel" and "Death and Transfiguration" -- played by the Cleveland Orchestra under Lorin Maazel (IM 35826). The products of CBS's Terre Haute plant, where special care has been taken to show that quality pressings can be made here. I heard a little crunch in "Petrushka," but otherwise these are exemplary pressings. (The factory-sealed" plastic outer envelope, though, is laughably easy to open and reseal.)

They are not all exemplary performances, though. Mehta's new "Petrushka" is an undistinguished as his earlier Los Angeles version on London. There are superior accounts of both the 1947 and, the more lushy scored 1911 versions, some on budget labels. The recording itself, made with the 3M digital system, is bright and clean, but rather lacking in depth and with a good deal less bottom than one might have expected.

The final movement was really too fast in Bernstein's earlier recording of the Shostakovich; but even so, that performance was charged with an extraordinary intensity and gutsiness, and had a remarkable sweep to it. In the remake, the opening movement is so extremely relaxed as to be virtually static, and with only minimal contrast between the dramatic and lyric episodes. The tempo per se is better judged than before in the finale, but the music does not seem to come to life. This recording and the others discussed below were made with the Sony PCM system, which makes a better showing here than in RCA's Dallas series, but lacks both clarity and punch in the low end.

The Prokofiev, too, is much more meditative and deliberate than Ernstein's Bernstein's earlier reading of the work. The noble slow movement is gloriously convincing, but the outer ones hold together well, the first almost painfully slow and subdued. The sound, a little coarse here and there, is not much of an incentive in its own right. Bernstein's earlier recordings of both these Russian Symphonics remain far more persuasive than the new ones.

The bright spot in this assortment is Maazel's Strauss collection. The performances are perhaps even more convincing than those he recorded some 15 years ago in London and Vienna, and the sound from Cleveland seems altogether crisper and richer than on either of the Bernbstein discs. These may not be the ultimate best recorded performances of these three works, but they are clsoe enough to constitute an asupicious first digital entry in the Strauss discography.

The CBS digital cassettes are "Dolbyed" and on chromium dioxide tape. The Shostakovich sounded a little blurred in the bass, but the Strauss is as handsome in this medium as on disc, surely one of the best cassette recordings yet offered by any of the big companies. The very best, though, are being offered by a much smaller one: In Sync's new "Real Time" series, also "Dolbyed," also on chromium dioxide tape, and also $14.98, delivers what is simply the finest sound yet achieved in this medium.

The 40 cassettes issued so far are for the most part new editions of the already outstanding original in Sync releases, drawn from the Connoisseur Society disc catalogue. No digital process is involved; the big difference is that each cassette was recorded from the master tape at its actual playback speed of only 1 7/8 inches per second, and each individual cassette was auditioned in whole or in part no fewer than four times during and after copying. The realism achieved through this patient process is incredible, with no perceptible limitations on either the dynamic or tonal range and yet no feeling of boosting or exaggeration. How much more, one must wonder, could be got out of all master tapes with this sort of care.

"Lifelike" is really the word for Ivan Moravec's incomparable performances of the Chopin Nocturnes (c 4025 and 4026), for Rachmaninoff's concerted works with Jean-Philippe Collard and the Toulouse orchestra under Michel Plasson (C-4001/4004), for All Akbar Khan's "40-Minute Raga" (C 4038), and in fact for just about any of these tapes one might choose. There is not space to list them all, but the most impressive is the 1971 recording of the Greig and Ravel sonates by violinist Wanda Wilkomirska and pianist Antonio Barbosa (C 4035), in which one feels the shimmer, warmth and overall presence of the two instruments exactly as one would in an ideally proportioned room containing just the right amount of furnishings and listeners. To hear these well-loved performances brought to such glowin new life is an experience beyond price, as well as beyond what has heretofore been expected of the cassette medium.