It's funny how quickly the music market adapts to new technology. Two years ago, it was hard for pop music fans to find even the hits on compact disc; now, not only are they available in abundance, but there are even CD releases that can't be found on vinyl.

One typical source for these recordings is Private Music. A small label founded and run by Tangerine Dream member Peter Baumann, its projects are recorded digitally and are available only on CDs and chromium dioxide cassettes. This high-tech approach is in keeping with the electronic orientation of the label's artists, who at the moment include a pair of synthesists and an electric violinist, but hardly colors the music esthetics.

In fact, Sanford Ponder's "Etosha" (Private Music 1101) begins with the rumble of thunder through a forest of chirping crickets and chattering birds. Never mind that the sounds exist only as digital "samples" in the computer memory of Ponder's Fairlight synthesizer, or that the thunder serves a suspiciously musical function in the statement of the opening scene. The point is that the illusion created here works well enough to distract the listener from the artificiality of Ponder's electronic environment.

There's nothing particularly novel about high-tech musical pastorals; the Japanese composer Kitaro has built an impressively profitable cult around the pseudo-Zen of his synthesizer pieces. But Ponder avoids such cartoonish simplicity in his work. Although the sound effects lend both atmosphere and poignance to the pieces, they are never allowed to dominate. Instead, the compositional ideas stand on their own, and as a result, it's the freshness of Ponder's musical vision rather than the richness of his sonic palette that wins over the listener.

Because the array of sounds obtainable from the latest generation of synthesizers is so seductively vivid, maintaining the balance between art and technology is no easy feat. Patrick O'Hearn's "Ancient Dreams" (Private Music 1201) employs many of the same shimmering textures and resonant tonal colors Ponder proffers, but lacks the corresponding compositional consistency. O'Hearn, best known for his work with Missing Persons, seems a group player at heart, and as such is at his best when working off trumpeter Mark Isham or the three percussionists who flesh out the pieces here. All too often, though, the moody atmospherics of these pieces tend to dominate, allowing the music to drift aimlessly into the ether.

Despite the high level of technology employed on these recordings, the compositional devices tend to be rather simplistic, as befits pop instrumentals. Trouble is, that can lead to a sense of sameness in the songs; how many times, after all, can O'Hearn prop up a wistful melody with a circular, arpeggiated chord progression before it begins to sound as if he's recycling the same overused ideas?

Jerry Goodman's answer to that problem is to build tension through repetitious ostinato vamps, and then release that pent-up energy through virtuosic solos. If that formula rings some bells, don't be surprised; Goodman worked within a similar format in the early Mahavishnu Orchestra. "On the Future of Aviation" (Private Music 1301), however, avoids the sort of instrumental overkill that has long been the bane of fusion jazz.

Sometimes, though, blending into the background is precisely what an artist intends. That's clearly the case with Brian Eno's "Thursday Afternoon" (EG EGCD 64), a CD-only edition of music composed for a video commissioned by Sony of Japan. The music certainly suits the CD presentation -- for one thing, at 61 minutes, the piece couldn't exist in any other format -- and the digital sound's combination of quiet and clarity is perfect for Eno's bell-like piano treatments and vaporous harmonies.

Unfortunately, "Thursday Afternoon" resists close listening, as its loosely organized themes and deliberately understated textures seem almost to evaporate on their way out of the speakers. True, it's more intellectually demanding than Muzak, but it's still not as satisfying as silence itself.