In the world of digital music, there's been a longstanding divide between the hardware synthesizer and the computer. You can hook a keyboard controller to a computer, or even build a custom Windows PC into a keyboard frame, like the OpenLabs NeKo. Fundamentally, though, the two categories have remained distinct—until this year's launch of the Korg OASYS, that is.

The designers at Korg have built a super-keyboard that fuses the open platform of a PC with the dedicated, proprietary sound engines of a traditional hardware synth. With its uniquely deep sound-production capabilities, the OASYS, whose name stands for Open Architecture Synthesis Studio, is more than a traditional electronic keyboard. And it's also more than a computer, with lavish audio quality that high-end audio workstations struggle to match.

Even if you can't afford an OASYS—Korg acknowledges that the $8,000 sticker price will limit its audience—a look inside this mammoth keyboard reveals a lot about how a high-end digital musical instrument can be created. It's certainly a glimpse into the future of Korg, but it offers insight into the future of the musical instrument industry, too. And, perhaps for the first time, the words digital and luxury come together in a profoundly musical instrument that's a dream to play.

I got a chance to spend some time with Korg research & development product manager Dan Phillips and Korg USA keyboard and recording products manager Jerry Kovarsky to get hands-on with the OASYS and find out what makes it tick. I wanted to know, as many digital musicians do, what kinds of decisions go into creating an instrument using today's technologies? Do the craftspeople behind modern digital instruments have the same kinds of interests as traditional instrument builders? How do you turn a sophisticated, Linux-based hardware monster into something that works onstage? The answers often come down to subtle technical details that many casual onlookers would easily miss. (And, yes, I found out why an OASYS is so expensive, too.)

OASYS Angle The Korg OASYS workstation combines high-definition synthesis, hard disk audio recording, multitrack MIDI sequencing, KARMA algorithmic music generation, a control surface, a touch-sensitive color display, and a CD burner for rendering your compositions. Inside, a 2.8GHz Pentium 4 processor runs Linux, permitting feature updates. A new one was just announced this week.

What Makes OASYS . . . OASYS

The OASYS has high-end specs galore. Inside its road-ready frame a 2.8GHz Pentium 4 runs an integrated Linux-based operating system and a proprietary sound engine that represents decades of Korg's sound design experience. On the outside, it's all keyboard, sporting 76 or 88 keys (synth or hammer action), a 10.4-inch color LCD screen, and a control surface with drum pads, chord triggers, joysticks, a ribbon controller, and assignable switches, knobs, and faders. Its three sound engines, offering analog modeling, tonewheel organ, digital sampling/synthesis, and combinations of the three, can play as many as 172 voices at once.

But when Jerry Kovarsky wants to show off the OASYS, he doesn't mention specs. He lets that 172-voice polyphony rip. Running his arm across the keyboard's eight octaves, Jerry sends the OASYS into a roaring Hammond organ glissando. The heavily layered patch doesn't blink. "Try that with a soft synth," he says, flashing a kid-with-a-Christmas-toy smile. When the OASYS was unveiled at the NAMM show in January after years of rumors and anticipation, people didn't talk about specs. The buzz, aside from the price, was all about how the OASYS sounds.

Despite its forward-looking features, the OASYS design has a long, interesting history. It's the culmination of work stretching back to the early '90s. The current product resulted from a collaboration between Korg R&D in California and Korg, Inc., in Japan. The U.S. team, including Phillips and many others, focused on sound generation and processing aspects while the Japanese team worked primarily on the hardware, user interface, sequencing, recording, and KARMA (Stephen Kay's algorithmic music engine).

Original OASYSThe prototype OASYS (bottom, in a museum display commemorating Korg's 40th anniversary) was so far ahead of its time that it never shipped. However, Korg spun off parts of the OASYS physical modeling technology into more affordable instruments like the monophonic Prophecy (top).

Although this is the first shipping keyboard to bear the name OASYS, Korg has shipped products based on the same technology; the same R&D team developed the original OASYS keyboard prototype and the later OASYS PCI, a PCI card and software platform for PC and Mac. "Many of the underlying algorithms are carried through from those earlier projects," says Phillips, though he and Kovarsky emphasize that Korg has optimized and expanded nearly everything. If the OASYS PCI sounds were the originals, then each OASYS keyboard sound is a "special edition" extended version.

How did Korg go from keyboard to PCI card to keyboard again? "The whole idea was that you'd have a system that was upgradeable, that wasn't based on dedicated hardware to make the sound," says Phillips. Most digital audio gear relies on specialized chips called ASICs (Application-Specific Integrated Circuits, pronounced "AY-sik"), as opposed to the standard, generic integrated circuitry of a computer. In other words, each time you want to build a new musical instrument, you create new, specialized chips for the job. That keeps production costs down on high-volume products like the Korg Triton, but freezes the design, so the basic synthesis method of the instrument is not upgradeable, except via additional hardware.

Computer circuitry provides much more power and flexibility, but it's labor-intensive and expensive to create, produce, and program for use in musical instruments. The idea of OASYS was to meet the challenges of the open-platform design while choosing specifications that turned the keyboard into a luxury item, rather than a low-cost commodity instrument.

Korg Does Linux

The OASYS doesn't just have standard PC circuits; it runs on top of PC software. It's the first big-name music product to run Linux. (Muse Research and Manifold Labs offer Linux-powered, rackmount plug-in players.)

Getting an operating system working on a musical instrument is a little different than installing it on your PC, though. "We are using a real-time extension to the kernel," says Phillips. "Through the real-time extension, OASYS doles out CPU cycles to other processes. With a real-time system, it's something that actually owns the hardware, and the operating system kind of runs on top of that."

Under the hood, the OASYS is running genuine Linux as its OS, and Phillips says the GPL—the General Public License, the legal license that governs open source software and keeps it free—still covers the Linux kernel and some GNU utilities. (Naturally, the GPL doesn't cover Korg's proprietary OASYS software, but you will find applicable source code and licenses on the bundled CD-ROMs for the open-source Linux components.)

Touchscreen DisplayThe touchscreen display gives easy access to the innards of the OASYS, complementing the physical control surface to its left. (Click to enlarge.)

So you boot up your OASYS and see a Linux log-in screen, right? No way. Linux is entirely behind the scenes. "Basically, [the operating system] doesn't include anything that we consider to be the heart of the system—the synthesis, the UI [user interface] are all proprietary," says Phillips.

"You have three choices when you build hardware like this," he continues: "Not use an OS at all; create your own OS, as Korg has done with other devices; or get an OS from someone else." Using an existing OS is fairly new in the world of musical instruments, but it's an enormous time-saver. "Most of the work is already done," Phillips explains. "It was really good to have a relatively off-the-shelf operating system, because of the complexity involved in building the other elements of the OASYS."

The decision to go with Linux over Windows or another OS was straightforward. The OASYS PCI ran on Windows systems, but licensing embedded versions of Windows to run on keyboards is prohibitively expensive. Windows also does lots of things you don't need a musical instrument to do. "The clearest path was towards something we could customize for ourselves, that would be really reliable and would allow real-time performance, says Phillips. "Linux seemed to be the best choice, in combination with real-time extensions."

In fact, Linux's greatest success on the OASYS project may be that it's almost entirely invisible, letting Korg's designers focus on their proprietary sound engine. That was a big part of the appeal to Korg. "You can change things easily in Linux," says Phillips. "There's more granularity when you compile the kernel."

Developing the OASYS Engine

Jerry Kovarsky Korg USA Keyboard and Recording Products Manager Jerry Kovarsky (photo: Dan Phillips).

When players say the OASYS—or any other synth, for that matter—"sounds good," what's the reason? Aside from raw digital-audio resolution, there are a number of factors at play.

One major accomplishment of the OASYS is a bit hard for synth newcomers to appreciate, though digital synth geeks get it immediately. It's called dynamic voice allocation, and it's what separates the OASYS from other hardware and software, computer-based synths included.

Voice allocation is what allows a synth to play multiple notes (which in turn often include multiple, layered sounds) at the same time. Adding multiple synthesis engines, as the OASYS does, complicates matters. Most digital synths can't allocate notes between different synthesis engines; even the OASYS PCI lacked this capability. Your computer can dynamically share resources among multiple effects and synths, but the process is often inefficient.

"The big issue comes when the resources aren't sufficient to carry out the tasks the user is requesting—for instance, playing more voices than the CPU can handle when using multiple synth plug-ins," says Phillips. "In this case, with CPU systems, there is generally no overall management; an individual plug-in will most likely allow the user to set a max number of voices, or perhaps a max CPU percentage, and then steal its own voices to keep within those boundaries, but one synth can't steal voices from another synth. Instead, when you ask too much of the system, you get dropouts, stuttering, and other symptoms of CPU overs."

Your CPU is also busy drawing the GUI, handling audio playback, and doing other chores. Many software synths make compromises to go easy on your CPU, like limiting sound quality or setting arbitrary limits on polyphony. Beyond that, you wind up doing the allocation of resources yourself, manually: You watch your CPU meter and make adjustments to keep it from overloading.

"What we've done in OASYS is rather different," says Phillips. "We have a manager for all the voices in the system, a voice allocator." That makes a big difference in the richness of the sounds the OASYS is capable of producing. "The more voices you have, and the more channels that you have, the more complexity in a voice itself," Phillips notes. Kovarsky's forearm-mashing demo bears that out: The OASYS is filled with stunning, rich patches that layer complex, high-quality audio.

OASYS players don't have to worry much about what's going on under the hood, but with multiple synthesis engines it gets pretty complex. "The AL-1 virtual analog, the CX-3 organ, and the HD-1 PCM synth all require a different amount of computational power per voice," says Phillips. The CX-3 organ has both static and dynamic components to manage. With all of this allocation complexity, using a single, very powerful CPU instead of a set of specialized DSP chips can be advantageous, says Phillips.

Dynamic voice allocation is just one aspect of what makes the OASYS sound the way it does. "Many, many man-years" at Korg went into voicing, the painstaking process of tweaking preset sound data to make it sound just so, says Phillips. In the same way that craftspeople voicing a Bösendorfer or Steinway piano make the sound of those instruments unique, the human touch on any instrument is invaluable.

OASYS controllersThe controller section is carefully mapped to each sound, simulating drawbars on Hammond organ sounds or volume faders in mixdown mode, for example. Also note the vector joystick, used for blending four sounds.

Going beyond the presets is important, too. A major design goal of the OASYS was customizability. Korg wanted audio and modulation routing to be extremely flexible, and it has made extensive use of the hardware control surface, so that knobs and faders function consistently across instruments and always are capable of doing something to the sound. While much of the focus is on the OASYS as a synth, it's also capable of live sampling, beat detection, and slicing. Combined with audio recording and arrangement capabilities, this is really a full-featured workstation keyboard capable of many tasks without a computer.

Following the OASYS

The OASYS keyboard is just the beginning of the road. Korg has been known for extending synthesis technology across its product line; witness its MicroKorg keyboard version of its virtual analog MS2000B synth, the extensive ElecTribe and Kaoss Pad lines, or the Legacy Collection software versions of its vintage hardware. You can bet some of what's in the OASYS now will be in other Korg products later. And the OASYS itself is designed to be highly upgradable, so that you won't have to continue the cycle of buying new gear to get new sounds.

"We're intending this as a platform," says Phillips. "The main OASYS idea is when you find a new synthesis method, you don't have to build new hardware for it. On the one hand, you can have a system that's designed to work as a musical instrument, which is designed to be integrated. And on the other hand, you can add things to expand the system without changing the hardware underneath it." Unlike with a PC, you won't be downloading a half dozen new plug-ins from the Web every other day, but when Korg does decide it wants to release a mammoth new synthesis architecture, it can.

In fact, Korg has announced the first of these expansion instruments, the STR-1 Plucked String instrument, as a free software upgrade due in December. The STR-1 is a physical model of a string, using a technique called waveguide modeling. (Similar synthesis techniques are employed by the Sculpture synth in Apple Logic Pro, and in Native Instruments and Applied Acoustics software.) By accurately modeling the way a string behaves when it is "excited" (via plucking, striking, scraping, and so on), the STR-1 can realistically reproduce instruments like guitars, basses, Clavinets, harpsichords, and bells, as well as create new, imagined sounds.

One of the exciting possibilities of the STR-1 is the ability to realistically create harmonics, and even damping at harmonics, as is possible on real-world cellos, guitars, and other instruments. Flexible routing lets you layer the STR-1 with other STR-1s or other expansion instruments, and even route live audio into the engine. For more on the upgrade announcement, see Create Digital Music.

OASYS on WhiteThe hammer-action, 88-note OASYS, cleared for takeoff. (Click to enlarge.)

One beloved feature of the OASYS PCI platform, the SynthKit software for building your own plug-ins, isn't yet available for OASYS. That software was released unsupported for the OASYS PCI; hopefully Korg will follow suit with the OASYS. But you can certainly expect more instrument expansion from Korg. One Korg representative hinted that Frequency Modulation (FM) synthesis, as popularized by instruments like Yamaha's DX-7 and software instruments like Native Instruments' FM7 and Ableton's Operator, is a strong possibility, probably launched under Korg's name, VPM. Thanks to the Open Architecture design of the OASYS, the upgrades are software-only; no new hardware is needed. If the first three synthesis methods are any indication, OASYS owners are likely to find additional expansions worth the wait.

The Luxury Synth

Dan Phillips Korg product manager Dan Phillips has been happily steeped in OASYS technology since the beginning.

So, ultimately, why buy a Korg OASYS instead of a computer and a pile of high-end software and peripherals? For Kovarsky, it's about having the capabilities of a computer, but "without fear"—of crashing, or overloading the CPU, or running out of polyphony, or configuration, or the other details of maintaining a PC—as well as getting audio quality that's impossible with a PC alone.

For some of OASYS' high-profile celebrity users, it's about the ability to create new sounds in a reliable, road-ready rig. Herbie Hancock, always one to drool over new gear, is already taking advantage of the OASYS in performance, morphing clav sounds into elaborate wave-chained sounds, says Kovarsky.

Ask Dan Phillips, and you'll get a more specific technical answer: "We have 172 voices with probably the best real-time interpolation available today, so you can play sounds in which the high frequencies aren't attenuating, yet you get really good anti-aliasing response." Or, more plainly, he says, "I don't think you're going to find something that sounds like or functions as smoothly as the OASYS. Speaking as someone who's been working on synthesizers for 15 years, there are very few plugins that sound very good. For some sounds, you may not be able to tell the difference, and in a mix some of the differences are lost . . . but there are a lot of areas where these things fall down."

It's not that software plug-ins sound bad, necessarily, just that software must always make a trade-off between performance and sound quality. "I would say the [Korg] Legacy MS-20 is a pretty good example of a pretty good-sounding software synth," Phillips contends. "The [Way Out Ware] TimewARP 2600 is another example. But those two things have a lot in common—one of them is that that they require a whole lot of processing juice."

Since the OASYS is a relatively closed sound-production environment, it can make full use of the CPU resources available. Software running as a plug-in in an open host on top of a PC operating system has none of these advantages, and it has to be targeted to a range of computers.

Korg is aware of the price difference between OASYS and competing solutions, says Phillips. "Three guys with dime-store guitars can make pretty good music. Korg isn't saying you need to drop eight grand on a keyboard to make good music. What we are saying is to get the kind of sounds you can make on OASYS, this is what it costs. If we could do it cheaper, we would."

Even if you can't afford to buy an OASYS for your studio, it's worth trying to steal a few moments on one to see what it's like to play. It's a tremendous experience, one that may inspire the next generation of software and hardware instrument design.

"Our concern has mostly been, how do you make a really great synthesizer?" says Phillips. "We've been working on that for about 15 years."

Exploring the OASYS

Dan Phillips Interview Create Digital Music's extended interview with the Korg R&D product manager. (Phillips' home page is quite interesting, too.)
Original OASYS Photos and background on the 1990s OASYS prototype, plus spinoffs.
OASYS Product Page Offical OASYS page, including audio demos.
OASYS Virtual GUI Test drive the OASYS touchscreen interface from your Web browser.
OASYS KARMA Background on the Kay Algorithmic Realtime Music Architecture (KARMA) features in OASYS. Includes extensive audio and video demos.
The Making of the Korg OASYS Unveils the human side of the OASYS design process, including how the instrument wound up with the code name Pocky, after the tasty Japanese snack.
Keyboard OASYS Review Find out why the premier synth magazine said, "Korg set out to create a first-class instrument, and they succeeded. If you want to sound like you and no one else, I can think of no other instrument that makes it more possible than this one."


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