Steven Sinofsky showing Windows 8 last year. Photo (CC-BY) BUILDWindows.

There’s good news and bad news on Windows 8 for music making. If you’re using Windows on a conventional, Intel PC, running conventional, desktop Windows apps, the news is really all good – really good. It’s still early days, but Windows 8 promises to be better than Windows 7 at audio performance metrics across the board, a no-brainer sort of upgrade for music makers.

By contrast, if you’re using Windows 8 on a new ARM-based tablet or interested in seeing music apps that take advantage of the new-fangled store and app coding style, the news is looking really pretty bad.

I’ve talked with various developers; Cakewalk CTO Noel Borthwick has been uniquely involved in researching what’s changed. He now releases details of how the developer tools work in Windows 8, as well as how desktop acts can be expected to perform, using an unmodified version of their SONAR DAW you may have running on your PC right now:

WINDOWS 8 – A BENCHMARK FOR MUSIC PRODUCTION APPLICATIONS [Cakewalk Blog]

For background, in 2009, Noel looked with us under the hood of Windows 7 – and everything there is relevant to desktop Windows apps today under Windows 8, with further improvements added in the new version of the OS. (See below.)

That is a must-read for the technically minded, but in case you’re not a developer or haven’t kept up with everything happening with Windows 8, I’m going to explain some of the background. I’ll look at the fundamentals of the new OS – or OSes, really – and then explain why one particular point on the version of Windows 8 you’d likely run on many tablets has a big deal-breaker for audio. (Opinion: These are my opinions, and my take on the engineering analysis as I understand it, not Noel’s or Cakewalk’s; it’s worth getting those ideas out there now in advance of the OS release as we expect to learn more as the thing ships.)

What It’s All About

Let’s explain, in terms as simple as possible. The easiest way to think about this is Standard Windows and New Windows. (I’ll say “standard” rather than “old,” because the “old” in this case seems to have gotten a lot of love and attention, and clearly isn’t going away.)

“Standard Windows” is Windows as you now know it, with years of experience in audio APIs that make Windows computers powerful for music applications. It’s the Windows that lets your hardware work, lets you plug in keyboards and audio interfaces, lets you run all the audio software you use, and get low-latency performance for virtual instruments and recording and anything else that makes sound. It’s not always friendly – installing special drivers and whatnot – but it does work. And it works not only for “pros,” but also “amateurs” who want to make music and don’t appreciate unexpected delays between when they do something and when they hear a sound. It works on computers that are general-purpose machines used by “punters” as the Brits like to say, people having nothing to do with music. Standard “Windows 8″ is, simply, Windows running on Intel as you know it.

“New Windows” is based on some, but not all, of those ingredients, and introduces software that looks and works a bit differently than the Windows you know. It’s Metro running on Windows 8, the new design language involving all those colored square tiles you see, and now a set of graphic APIs for writing to it. It’s not the “old” design language you’ve seen in, say, Excel – or SONAR or Cubase – running on Windows 7, the business with the red X button and the transparent window bars. Then, there’s WinRT (short for Windows Runtime), a set of developer tools that let you code applications for “New Windows,” and distribute those apps in a new, Apple-style app store from Microsoft.

If you’re running a PC and you install Windows 8, you get both “Standard” and “New” Windows on your machine, and you can run each of the apps. So, when you do want to use Ableton Live or Cubase or SONAR or FL Studio, the Windows you know is there. If you want to look at a bunch of colored tiles or play some Angry Birds or use a Twitter app made for Metro, you can run that, too. You’ll find yourself buying those apps from a store, the way you do on an iPhone. The same is also true of the upcoming Surface Pro tablet: it’ll do both, which is why I think it will be uniquely interesting to musicians. (For some, it may be more interesting than even the iPad, because it won’t make you give up the apps you already use on your laptop or desktop machine.)

There is now, however, a breed of “Windows” computers that gives you no choice. Microsoft’s own non-Pro Surface is one example. These machines have ARM chips instead of Intel. And with just one set of exceptions – Microsoft’s office apps – they won’t run “Standard Windows.” They’ll only run the new-fangled Metro and WinRT stuff, via an operating system confusingly called Windows RT. Window RT is kind of Microsoft’s answer to iOS.

Ah, you say, but this is a good thing. If I’m using a slim, touch-only tablet, I don’t want a bunch of “legacy” apps that aren’t built for the new UI metaphors.

You’d be exactly right. And that’s why the bad news is really bad news if you were eyeing those machines. (Well, unless you like latency, in which case, I have, um, terrific news! You’re REALLY going to love the long moments of peace and quiet between when you strike a note and when you hear a sound! It’s not latency – it’s moments of contemplation!)

The Bad News About WinRT

Some of WinRT’s design is familiar to users of Android and iOS. You can’t really install plug-ins. (You can use native code, so, in fact, there’s nothing stopping things like libpd from working on Metro – complete with support for externals.) Okay, so, no deal-breaker there.

There’s also no support, at least that we can tell, for audio or MIDI hardware. That’s kind of a deal breaker, given you can take a range of audio and MIDI hardware and plug it directly into an iPad. But, part of the advantage of a tablet is portability, and this is a first-generation product, so let’s give them a pass there.

There’s WASAPI, the low-latency audio framework first seen in Windows Vista. Okay, that’s good news – low-latency audio framework. That’s what’s missing on Android, and what’s present (as “Core Audio”) on iOS, the guts that have made all these music apps possible on iPhone, iPad, and iPod touch.

Now, here’s the deal-killer: it’s missing the low-latency bits. Noel explains:

WASAPI supports low latency via what is known as “exclusive mode” where an application can bypass the high latency introduced by the system mixer. However based on reports from Microsoft it would appear that low latency audio applications were not considered in the Metro application model. See this blog post where Microsoft states that 100 msec was considered to be their goal for acceptable latency!

Updated: Just to clarify, since some folks are questioning whether this is as bad as it sounds, the issue is, without Exclusive Mode you do need to route audio through a device mixer that allows simultaneous audio from multiple apps. That’s a source of this latency and why you see the 100 ms figure. We’re still researching to find out if there really is no Exclusive Mode available in WinRT, but presently, it at the very least isn’t documented and isn’t working in apps.

Oh, yeah, and with no low-level support for driver models to replace that, you can’t plug in your own hardware to get high-quality, low-latency audio that way. You’re just, uh, out of luck. (Someone suggested that Steinberg would release ASIO for WinRT. That might be the case, if it were possible. Based on current documentation, it’s not. It would also need to be in the form of a device-specific library, released with each app, based on other development requirements, so you really do need this in the OS.)

Unless we receive new information, that means it’s safe to describe Windows 8′s WinRT as completely tone-deaf. It means Microsoft learned none of the lessons of what Apple accomplished, and what Google failed to accomplish, that really nailing the quality of your multimedia layer in software.

If this developer information is correct and complete, it would Apple raised the bar, and then Microsoft lowered it again. And it’s especially unforgivable, because unlike Google, Microsoft actually does have experience at this. Which brings us to the good news – for desktop users, that is.

Windows 8 is Looking Better Than Windows 7

Noel testing SONAR under Windows 8. Courtesy Cakewalk.

Desktop users, if this was making you feel bleak, don’t. It’s just a first benchmark, so should be taken with a grain of salt, but in testing SONAR on Windows 8, Noel finds a litany of performance improvements across the board, in areas like:

  • Hard disk throughput
  • Lower CPU load in low-latency situations
  • Reduced memory usage
  • Overall reduced CPU load and fewer audio glitches, thanks to improvements in the kernel and “system calls”

In short:

The results of the benchmarks were surprisingly good! Windows 8 performed better than Windows 7 across the board in all categories, and in many cases with fairly dramatic performance gains.

Why This Matters

The logical conclusions here:
1. Windows 8 will probably be a great upgrade for musicians on the desktop Windows platform.
2. For people wanting to run the new software environment, or use new ARM-based tablets, we’d need some evidence to demonstrate that this is a usable OS for music. Based on current information, it’s not – not for many applications.

You should read Noel’s analysis, but he reaches similar conclusions.

Here’s the rub: the fact that Windows 8 is so good when running conventional apps almost makes it more frustrating that so many new tablets will be left out of the party. Now, you could argue that “average” users don’t need such things, and I’m just a “niche” musician droning on about something that matters to me – and you’d be partly right. But average users share some of the same powers of perception with sound that advanced users do; there’s actual research on that. Average users can hear, and respond negatively to, 100 ms latency. And average users have made the iPad and iPhone some of the most successful products in history. Whether this was a deciding factor, it didn’t stop the mass market from buying them.

You could also argue that low latency concerns would make too great a sacrifice in battery life or app security. There, not only is the iPad evidence to the contrary, but so, too, is Windows itself. Not all apps need these features, but then why not build them into the OS for those that do?

If Microsoft really did fail to learn from their own engineering accomplishments on Windows, then it’s the obligation of those of us who do know something about sound to be, well, noisy about it.

When stuff works, it usually doesn’t work by accident – that’s true of all the OSes available today.

I’d love to be proven wrong, before Windows 8 ships on these devices. We’ll be watching, and will have more complete advice for musicians on all these platforms as these tools become available.

  • http://www.deeflash.com deeflash

    It’s amazing Microsoft missed the boat with Metro music apps.  Have they not seen the thousands of YouTube videos of iPads being used for music?  I’m sure smart coders will find a way around it but it’s really too bad that someone is not paying attention in Redmond. 

    • http://www.facebook.com/ghmetcalfe Graham Metcalfe

       I’m sure the idea is to move musicians and other content creator types to the Pro model where there is probably a greater profit margin.

    • DustinW

      MS’s goal is to move units of Windows8 … the MS Surface tablets are just being announced so that in November people can decide between a Asus/Acer/Dell tablet with Android or Win RT and the Win RT one will look good because for 50 bucks more then the Android version it comes with Office and Skype pre-installed. 

    • http://www.deeflash.com deeflash

      Yeah but they want musicians and other content creator applications to still use Desktop or Metro?  That’s more what I mean, a whole generation of software is going to completely ignore Metro if you can’t do anything real creative with it.  And now you can run iMovie, GarageBand, etc on an iPad.  That’s what I meant by MS missed the boat, the iPad can create content and if that’s what they’re aiming for with the ARM processor tablets, they are not going to be able to compete with terrible latency.

  • erja

    Speaking of Android audio, has anyone seen the galling advertising for a symphony of HTC (I think) tablets playing an orchestra?  Lucky for them lawyers probably aren’t interested in the intricacies of Android audio latency.

    • http://pkirn.com/ Peter Kirn

      I’m working on finding out if they’ve made any improvements in 4.1. There’s a lot of new audio stuff in there, but none of it seems to address this issue. So — yes, if it’s the same old story, they’re next.

  • David

    Let’s wait for the facts. I can’t quite yet believe that the old pre-Win7 Microsoft is back. The one that keeps snatching defeat from the jaws of victory.

    I mean, 100ms, that’s not even good enough for a clock widget.

    • http://pkirn.com/ Peter Kirn

      These unfortunately are the facts – this isn’t just speculation; this is based on presently-available developer documents. That’s straight out of Sinofsky’s blog, the 100 ms figure. The only loophole *might* be that you could somehow override defaults that keep you from being able to use Exclusive Mode, but there’s no confirmation yet.

  • DustinW

    Something is a bit wrong with the interpretations of the 100ms goal … that is the goal for device to device and back again communication latency of under 100ms (and in the blog post they achieved 65 ms with the beta). 

    I just spent some time digging through MS’s api docs and there is specific “Real Time Communication” sample that shows how to do “low latency” media work:

    http://code.msdn.microsoft.com/windowsapps/Simple-Communication-Sample-eac73290 

    & the “msRealTime” flag for using low-latency audio in HTML5 apps. 

    http://msdn.microsoft.com/library/windows/apps/Hh767377 

    At this point I don’t have any WinRT compatible devices to test the communications sample with but I bet it won’t be as bad as the “100ms” goal makes it seem.

    • http://pkirn.com/ Peter Kirn

      Right, but just calling a flag “real-time” doesn’t make it so — ask your local Android developer. I think you may be right that that’s a network communication spec, but the concern is still unpredictable latency if audio is routed through the system mixer, hence the questions about Exclusive Mode. I expect part of the reason for Noel’s concern here is that this isn’t all new stuff – we’re talking a mixer architecture borrowed essentially from desktop Windows. So, losing that fix, i.e., Exclusive Mode, means losing a fix that specifically made WASAPI useful on the desktop (versus ASIO). You can see why someone might be concerned.

    • Noel

      I plan on writing a small WASAPI Metro test app to actually check this out when I get some time. The MSDN documentation doesn’t say that  exclusive mode is not available but the information from the MS blog is conflicting. If we’re lucky maybe the guy on the blog is mistaken :)  
      -Noel

    • http://pkirn.com/ Peter Kirn

      Right, and I hope this was clear in the post — the meaning of this post is:

      “AUGH! What I’m seeing looks would be really frustrating, Microsoft. I sure hope this isn’t correct. That is, cough, Microsoft **I sure hope this isn’t correct.**”

      I have no particular desire to be right, generally. This is one where I’d love – and I’m sure Noel would love – to be missing something. It’s possible there’s some way of enabling Exclusive Mode for apps that need it, so you can, say, build a little virtual instrument for Metro, etc.

  • David Prouty

     I am a Diehard windows user. I will be leaving windows after many years because this Metro interface breaks my workflow, and it also uses resources I would prefer to use for other things …. You can not turn it off so the Metro UI will constantly suck cpu ram etc. The current windows interface is the Microsoft Brand but they have just told all of their power users that we don’t get a choice in how the new environment functions for workflow……the old proven methods will need to be relearned.

    The new GUI is a joke. Current windows users will probably find Apple products more Windows like than Windows itself.

    Windows the good. Win 95, Win 98, Xp, Win7
    Windows the Bad. Millennium, Vista, Metro

    Every other operating system has been a resource hog. Every other operating system basically is bloatware. I need a powerful environment for what I do, not an underpowered paradigm shift of a operating system meant for a cellphone. It looks to me that they have given up on the Desktop environment. Power users no longer matter and mobile has become Status Que. I don’t care that they have left some semblance of the old GUI that you can switch to. I need an environment that streamlines my every move without throwing away the current metaphor. Windows could be better without recreating the experience from scratch.

    • http://pkirn.com/ Peter Kirn

      “You can not turn it off so the Metro UI will constantly suck cpu ram etc”

      That’s not true. Read Noel’s tests. In his Windows 8 benchmark, running SONAR as a desktop application, Windows 8 used less RAM and less CPU. (and has higher disk throughput, and fewer system calls …)
      Just ignore Metro if you don’t like it, in other words. But the reality – and this to me is good news – is the exact opposite of what you’re describing.

    • Noel

      Right. This is the precise reason why I did the benchmark. I dislike the Metro UI as much as anyone else but you can’t make assumptions about whether its consuming resources that affect applications detrimentally without doing some hard objective benchmarks. The whole point of Metro is to run on tablet based devices and to consume less power (which typically means consuming less CPU or offloading CPU tasks to the GPU) so it would be silly if Metro consumed an inordinate amount of resources. All the metro UI is doing is painting those oversize tiles and Win 8 itself seems to be consuming less resources across the board than Win7 so its hardly a resource hog.
      Its too bad that they removed the ability to hide the metro interface for desktop users. One of the earlier CTP’s had a registry hack to disable it on startup.

    • David Prouty

       Well ok memory is not an issue from what you say, but I still think the GUI itself is a deal breaker. If we are to reinvent tried and true methods wouldn’t it be nice to get something really worth it like a ZUI Mindmap Metaphor? I do not think the current tree structure system is perfect and could be improved but giant square  boxes is going backwards not into the future.

    • Aaron

      You should probably try it before you knock it. I’ve switched all my workstations, including my DAW, to Windows 8. Once you learn 3 keystrokes (charms, desktop, start) you’ll be navigating it faster than you ever navigated Windows 7.

    • http://twitter.com/laserfloyd Lewis McCrary

      It’s entirely possible to run desktop and never see metro.  Wife uses a laptop running release candidate and for all she knows, it’s Win7.  Everything can be pinned to desktop using shortcuts.  It really takes some getting used to but I find it’s pretty easy to get around.  That said, 7 will be supported for quite some time.

  • papernoise

    The big question is: what’s the estimated market for music apps and how do they impact hardware sales? My speculation is that the impact is not so big so companies like Google and Microsoft just won’t bother investing man hours in developing a system that will run them.
    Microsoft cares as long as it’s their “desktop-style” version of Windows 8 because many people are using it to make music and that’s a market and a sales argument. They probably don’t care when it comes to iPad-style devices, because they know that most people just want to surf the web, post on facebook and play games on them.

    What I find kind of stupid is the fact that MS split up the interface in two different versions: good ol’ WIMP-style windows and Metro. It’s the usual MS attitude, not being able to leave the past behind when facing the future. They did an admirably bold move with metro, but they are spoiling it by mixing it up with too much legacy stuff.

    • http://pkirn.com/ Peter Kirn

      Right, but:

      1. Not all APIs are used by every app – ever.
      2. They’ve made the investment in those programmer hours; they’ve built these things already.
      3. Making a design decision sometimes isn’t even a matter of expending resources. In this case, I think we’re questioning the design decision.

      And as for whether people care about these things, I think in the sum total, they do – I do think software quality and engineering, not just looks and advertising, have contributed to the dismal performance of Android tablets in the marketplace. Not to mention, look at the ad money people spend getting musicians to use products. Here, it seems you’re unlikely to find discriminating musicians of any stripes using Windows tablets, if they can’t do interesting musical things. So nearly 100% of those people will simply go to Apple.

    • papernoise

      I had a sentence in my comment that was saying exactly that, but I deleted it (don’t know why). Even if the actual user base for music apps on iOS might be small (which I don’t have any data on, but I guess it’s not the case) the actual PR and image related implications are quite enormous. As you said, musc-apps are the gateway to cool videos where people show off their tablets, which in turn makes them a great marketing tools and lead others to do the same. So Apple certainly had their ROI on adding core audio to iOS. I still think MS has taken this in account, but maybe underestimates the whole thing, or maybe it just won’t fit in with their marketing strategy…

      About it being just a matter of design. Well it’s true, but design is nothing if it has no engineering to back it, and implementing a certain design might cost more time and resources than a simpler less effective one. I’m currently working on software for tables (as a designer) and we often have to deal with such problems. You maybe have a great design idea, but there are no available resources to actually turn that into reality, so the idea ends up in the nice-to-have list or gets dropped altogether.

      Sometimes it’s just that one feature gets into conflict with another one and you have to choose if you want to have both (which might mean more work) or choose one of the two and save some time.

    • newmiracle

      I would normally agree with the sentiment that the “kitchen sink” approach winds up turning into a big pile of mess, but I think in this case MS did the right thing.

      People always talk about how traditional desktops aren’t designed for touch use, and touch based systems aren’t conducive to desktop-style work (“The mouse is more accurate!”), but at the end of the day… they’re both *computers*. I think it’s silly that you can’t have one machine that works in “touch mode”, does touch-y things, and when you stick it on a stand and press “desktop mode”, you can use it with a keyboard and mouse.

      How many people are using their iPads for TouchOSC? At the end of the day, aren’t they just paying (at least) $400 for a 10″ external monitor that has 10-point multi touch? It just seems superfluous to me. It’s tethered to a computer for it’s functionality. Why not just give the computer the ability to do that itself?

      The response might be that “normal consumers” won’t care/need that feature. But what about developers? Sure, maybe you won’t make billions off of the CDM crowd. But I can totally see interesting gaming potential here. Maybe extending certain photoshop capabilities. And so on. But you won’t see those developers make that happen until the functionality is present. But it’s not present because “normal folks don’t need it”. It’s a negative feedback loop! Hopefully the Surface Pro helps make a breakthrough there.

    • Hello

       ”What I find kind of stupid is the fact that MS split up the interface in
      two different versions: good ol’ WIMP-style windows and Metro.”

      Choice. It’s hard.

  • newmiracle

    I wouldn’t be surprised if someone made some sort of program for metro that launches “traditional” Windows apps into fullscreen mode. Or that there would be some kind of traditional windows sound service that Metro apps would access. Or some other kludge.

    But that’s just what it will wind up being. A kludge. I think the biggest appeal of these units is that MS had an opportunity to create a “hardware reference device” for other OEMs. Graphics have to work this way. Touch has to work that way. And this is how the audio is going to work. It’s a real shame that they dropped the ball with audio for Metro and hence, ARM devices.

    At least we get a reference for traditional Windows approach to 10-point touch. That’s the second biggest story here, imho. No more wondering what kind of screens do what kind of things. No more wishing for four-figure 10 point touch monitors to drop in price. Hopefully this standardization helps makes things more stable, helps developers take advantage of the features, results in killer apps, more demand, and lower prices for 10 point touch (minimum).

    It looks like worst case scenario you’ll start up your tablet, look at a pretty Metro weather widget, and go straight into “normal” windows. On the desktop you’ll have shortcuts to vvvv, usine, etc whatever touch friendly apps you want. It’s a shame it has to be that way, but it’s totally work-able. Even if it eventually results in 3rd party “designed for touch” interfaces that sit on the traditional Windows enviroment.

    • David Prouty

      “start up your tablet, look at a pretty Metro weather widget ”

      Just wait those squares will end up holding advertising …. Mark my words.

    • http://twitter.com/laserfloyd Lewis McCrary

      They won’t. Tiles can’t push ads because they won’t resolve to where the ad would take you if you click/tap the tile because you’re not actually in the app. Once you’re IN an app, all bets are off as most free apps rely on ads for support. :)

  • Hello

    Lord above. If you want to make music buy the Pro version. The cut down version is too slow, and it’s designed for consuming media. Microsoft have given you the choice – please let’s not whine that we can’t have both.

    If they can get the cheaper version to work better that’s great, but in the meanwhile there’s good news and we should be pleased about that.

  • Santiago

    This is just like when Apple made the switch from OS 9 to OS X back in the early 00′s. Lots of Mac users said they wouldn’t switch, that aqua used too much RAM, yada- yada.
    Apple made a compromise by shipping Rosetta with early versions of OS X which allowed folks to run legacy software, but as Adobe, Digidesign and others got on board this too was gradually phased out.

    I’m sure Microsoft will eventually phase out the desktop you all have come to love and hate over the years. The fact alone that they killed the start button is a telltale sign of where the OS is heading and anybody refusing to see the writing on the wall is simply in denial.

  • Shoeboy

    I think people are getting worked up over nothing.
    I’m chuffed to bits that Windows for me will not be having a drastic makeover.
    There’ll be those mentioned improvements plus the ability, finally, to use multitouch hardware.
    If I wanted a touch device that is restricted to approved software, fixed hardware and barely capable of running multiple programs…….I’d buy an ipad.

    I don’t remember ios shipping how it is today with an app store full of music apps.
    Funny how using an Apple product can cause selective memory.

  • http://twitter.com/ajscaldas Abraão Caldas

    Check out:
    How to enable low-latency playback (Metro style apps using C#/VB/C++ and XAML)
    http://msdn.microsoft.com/en-us/library/windows/apps/xaml/hh871376.aspx

    I´m correct?

  • West

    I swear I already posted a reply to this, but in case I didn’t, this post needs to be updated to reflect that low-latency drivers did make it into Windows RT. Check out the original Cakewalk blog post for further info.

  • Quityerwhinin

    Oh my gosh folks compaining about Win 8 Metro apps not being the powerhouse the desktop version is? Arm processors aren’t the processors the x86′ers are in general folks. And think about the investments you’ve made in HW and SW in making your studio work as fast as possible. I’ve been upgrading music equipment since SMPTE stripers on 8 tracks using the atari ST for midi and all outboard equpment, it’s been along haul and this particular upgrade is a no brainer from win 7 or mac’s. MS has improved performance significantly with your existing hardware. I mean – you want that and to have it in a metro app on a surface RT? You’ll be able to work it on a Surface pro sillies. Talk about first world problems. This is fabulous news all around. And I’m sure in the long run we’ll have uber performances in the tiled environment, but who cares right now… Being enabled to have your tools perform better than before in the desktop environment for a very inexpensive upgrade and throw in a new interface that’s intended primarily for consumption or less performant application usage when you’re not writing music, rendering 3d or creating the latest fractal masterpiece – coupled with seamless experience across Phone, Tablet and Desktop – come on… It’s really fab. I’m super impressed at the performance increases soley through software innovation, in an open hardware environment, with additional features rather than having to go buy new hardware to support your cool new features of the latest software… Sheesh what’s a company got to do to impress folks?

  • Aaron

    Update: WinRT supports WASAPI exclusive mode as of release.

  • Garrantsson

    Put MIDI into WinRT!

  • Garrantsson

    Apparently, MIDI was in the USB API in a “leaked” version of Windows 8.1 (http://justinangel.net/Win81APIs) but is now gone from the preview version.
    PLEASE, put it back!

  • Garrantsson

    Also check out my post (with the image and about UsbDeviceClasses) at MS: http://social.msdn.microsoft.com/Forums/windowsapps/en-US/72f78574-02c3-4986-8d5f-623b31c89765/midi-devices