IT'S ONE OF THE little ironies of today's digital culture that the least visual of the arts -- music -- has started to generate some of our most interesting visual interfaces. MP3 skins already constitute the best example of grassroots interface design, coating music players with endless variations of fifties-style jukeboxes, Starship Enterprise consoles, mahogany-paneled armoires, and other more exotic fare. And the plugin format translates the shifting EQ levels of audio into dynamic visual images, treating music listeners to the kind of virtual fireworks and fractals that used to require a few grams of psycilobin. But another region of the music world has also been pushing out some striking new designs. While our word processors, spreadsheets, and graphic applications share the same basic conventions as their predecessors from the early nineties, the software employed by actual musicians to create and edit their sounds on the PC has undergone a dramatic transformation. Indeed, today's audio-production software features some of the most radical interface design anywhere.

The funny thing about that transformation, though, is how backward-looking it turns out to be. A musician trained exclusively on the early music software of the late eighties or early nineties would find many of today's tools bewildering. But a musician trained in the older analog technologies of the sixties and seventies (Hammond organs or early synthesizers like the Prophet-5) would be immediately at home in these new programs. And that's because they have been meticulously -- some would say absurdly -- designed to mimic the look-and-feel of those now obsolete technologies: with endless banks of dials, patch cords, manual sliders, and other analog-era widgets. Playing with these programs reminds me of the old observation about the myopic futurism of the Flash Gordon serials from the thirties: Despite the fact that the series was set in the distant future, because the creators couldn't imagine a digital computer with a graphic interface, Flash is constantly tweaking dials and flipping switches, as though he were operating some kind of room-sized kitchen oven. Today's new music interfaces make me wonder whether those dials and switches are primed for a comeback.

It's a particularly interesting question, because that comeback has already begun on the level of the sound itself: the warmth and grain of tube amps, analog synths, and vinyl have attracted a growing subculture of fans, responding to the brassy digital productions (think Britney Spears or 'N Sync) that dominate the airwaves today. The question is: Is the return to both the look and the sound of analog tech simply a fad, like the disco revival or the return of Tom Jones? Or is it a sign of something fundamentally unsatisfactory about the intersection of music and the modern computer?

LAST WEEK, Sweden's Propellerhead Software released a new program called Reason, billed as an "infinitely expandable music system." Like many audio recording packages, Reason is as much a framework for future software as it is a set of tools -- though the initial group of tools that comes bundled with Reason are extensive enough, and include most of the basic building blocks of digital audio recording. There's a drum machine for laying down rhythm tracks, a sampler for triggering sound files from a keyboard, a number of units for adding effects like distortion or reverb to each track, a sequencer for recording and playing back entire songs, and a mixer for adjusting the levels. From that description, Reason sounds like a number of audio packages on the market right now, give or take a module or two. The real difference lies not in the functionality, but in what the software actually looks like on the screen.

What it looks like, in almost excruciating detail, turns out to be the sort of audio rack you'll see beside a keyboard player at a live show, or lining the walls of a recording studio: layers and layers of horizontal units, gleaming with LED readouts and pulsing lights, stacked one atop another. Manual dials and switches and sliders abound. (If Flash Gordon had a home studio, it would look something like Reason.) Reason's designers have even gone to the extent of including screws at the edges of the screen, reproducing the real-world screws that hold actual audio racks together. If you dedicate a module to a specific task (say, applying the reverb effect to the drum module), the software will display a little fake piece of tape with the fake handwritten words "Drum Reverb" on the effects module -- the way an actual roadie would do for a touring rock band.

Viewed on a large, high-quality screen, Reason is a spectacular piece of software. All those glittering diodes and 3-D knobs create far more eye candy than comparably powerful programs like Photoshop or Premiere. (Not surprisingly, of course: Visual artists don't like the distraction of overwrought interfaces.) But for all but the most experienced musicians, Reason's interface is also spectacularly confusing. If you don't know how a traditional rack of audio modules works, you're not going to get very far with Reason. All of which creates an interesting paradox: Propellerhead has drawn on all the visual firepower of the modern digital computer to recreate an interface that predates the icons, windows, and menu bars of modern digital computing. But surely there are better ways to represent what a reverb unit does than a series of LED numbers and enigmatic knobs?

The latest release of the popular Cubase audio recording system, for instance, takes a completely different approach. Since reverb is conventionally used to simulate playing music in different-sized rooms -- the difference between playing drums in a closet and playing in Carnegie Hall -- the Cubase reverb model includes a 3-D cube that grows in size as you adjust the sliders, giving you a clear vision of the acoustic environment you're simulating. That kind of immediate visual feedback would have been impossible with the crude LED displays of eighties-era equipment, much less the analog dials and switches of earlier technology. But it's a relatively straightforward feature for the faster video cards of today's PC.

Are there older, mechanical conventions that are actually worth keeping? The answer is probably yes. While Reason may have gone too far in reproducing the widgets of obsolete technology, the concept of the rack itself -- a series of distinct modules that you can string together into a single unit -- is an immensely useful idea, and one that translates brilliantly to the screen. Why launch another application every time you want to tinker with the drum loop? Why even launch another window? Reason's stacked modules let you fashion a unified audio system without forcing you to flip through menu options to access your core tools.

But Reason's most memorable feature lies on its backside -- oddly enough, given that software programs don't by definition have a "front" and a "back." Press a key and Reason "flips" the view to the back of the audio rack -- to a jungle of virtual cables connecting the various modules. Anyone who has ever maintained a music studio will instantly recognize that bramble of patch cords. Because so much of modern audio technology is about routing signals between different units -- the guitar played through the distortion box, and then EQ'd, and then mixed down with the drums -- the connected signal pathways that go into your average 'N Sync song are about as complicated as the air-traffic-control flight paths for the Northeast Corridor. And it turns out that one of the best ways to represent all those connections looks a lot like the way it looked when you actually had to make those connections yourself, before computers got involved with music production. You attached a cable from one unit to another. If you wanted to see how your audio system was wired, you walked around to the backside, and checked out the wires. The fact that Reason lets you do the very same thing on a PC screen is a genuine breakthrough, even if it's dressed up in the garments of dead technology.