MIDI Manufacturers Association Makes MPE Specification Official

Animoog is one of many synthesizers that support MPE.

MPE is now official.

The MIDI Manufacturers Association (MMA) has announced the ratification of a new extension to MIDI, MIDI Polyphonic Expression (MPE).

The specification, originally introduced as Multidimensional Polyphonic Expression, has also been rebranded as MIDI Polyphonic Expression.

MPE is a specification, based on MIDI 1.0, that creates a standard way to communicate per-note expressive information among electronic music devices and music software.

Here’s how the MMA describes it:

Prior to MPE, expressive gestures on synthesizers—such as pitch bending or adding vibrato—affected all notes being played. With MPE, every note a musician plays can be articulated individually for much greater expressiveness.

In MPE, each note is assigned its own MIDI Channel, so that Channel-wide expression messages can be applied to each note individually. Music making products (such as the ROLI Seaboard, Moog’s Animoog, and Apple’s Logic) take advantage of this so that musicians can apply multiple dimensions of finger movement control: left and right, forward and back, downward pressure, and more.

MPE is already widely adopted as a preliminary specification, supported by DAWs, like Logic Pro X, Bitwig & Cubase; software synths, like Cycling ’74 Max, Madrona Labs Aalto, NI Reaktor and Kyma; iOS music apps, like Noise, GeoShred, GarageBand & Animoog; and hardware synths, including Deckard’s Dream, the Futuresonus Parva & Modal Electronics’ synthesizers.

In addition, MPE can be used with some older synths that offer multitimbral support.

MPE’s early adoption was driven by the work of Geert Bevin, who wrote the original specification, and Roger Linn, who created the LinnStrument. it quickly became an important feature of iOS music applications, because of the way the iPad’s screen allows for multi-touch control of notes.

The standard’s widespread adoption has been driven by MMA members, including companies like ROLI, who has promoted MPE not just as a standard, but as a new platform for innovation in music.

MPE’s benefits have also been advocated for musically, by performers like Jordan Rudess, Eren Basbug and Marco Parisi, shown here in a 2016 NAMM Show performance:

The MMA highlights these key features of MPE:

  • Wherever possible, every sounding note is temporarily assigned its own MIDI Channel between its Note On and Note Off. This allows Control Change and Pitch Bend messages to be addressed to that particular note.
  • A Registered Parameter Number is used to establish the range of Channels used for sending or receiving notes. Two messages control the division of MIDI Channel space into sub-spaces called Zones, so that multi-timbral playing is still possible using only one physical MIDI interface.
  • When there are more active notes in a Zone than available Channels, two or more notes will have to share the same Channel. Under such circumstances, all notes will continue to sound, but will no longer be uniquely controllable.
  • Each Zone has a dedicated extra Channel, called the Master Channel, which conveys common information including Program Change messages, pedal data, and overall Pitch Bend. These messages apply across the entire Zone.

The MPE specification also defines how to handle Pitch Bend, Aftertouch and CC messages to provide maximum interoperability.

The MMA says that the official MPE specification will be available for download in the coming weeks via the MIDI Association site.

29 thoughts on “MIDI Manufacturers Association Makes MPE Specification Official

    1. It’s an open standard that anybody can use.

      Dave Smith never made money directly off of MIDI – just by being smart enough to make instruments that support it.

    1. MIDI clock, it’s implemetation, and how shitty it is in pretty much every single device on offer, really needs work. We know dedicated audio clocks do a much better job than MIDI does when it comes to sync

  1. Pretty impressive, but most of us don’t need to bend individual notes in a chord or other fancy features. The true MIDI evolution is still work in progress, imho.

    1. “Pretty impressive, but most of us don’t need to bend individual notes in a chord or other fancy features”

      Yet everybody wants a CS-80, which, besides its expressive capabilities, is a pretty limited synthesizer.


    2. > most of us don’t need to bend individual notes in a chord

      Not sure what particular group “most of us” subsets there, but it sure isn’t the general set of all musicians!

      Pretty much all music in the entire world throughout history makes much use of the ability to bend notes independently of each other, which is something nearly all instruments can do, with only few exceptions constrained to particularly limited and unimaginative instruments, most of which are rapidly becoming obsolete and good riddance.

      1. Probably missing the point again but can a piano bend notes? Can wind instruments bend notes independently at the same time. Or the voice? Surely the coolest thing about MPE is that with practice you’ll be able to do stuff that’s difficult to impossible on most other instruments. Not that those other instruments need to be tossed out. I know I’m likely exposing my ignorance or lack of sense of humour but there you go.

    3. Once you’ve put in some time playing a Linnstrument, you’ll never go back to playing plastic keys. But yes, if you want to continue believing that you don’t want or need individual expression per note, just don’t try playing a Linnstrument and you’ll be fine.

    4. Note indepent means that it can be done to a single note without affecting the rest.
      That is much more practically useful and musical than bending all notes playes independently at the same time.

      This also applies to the other types of expression included in MPE.

      Poly aftertouch was already supported by the midi standard.
      But MPE allows for at least one more of Modulation that can be note independent and I don’t think that is too complex, especially if they are used as diffent types of mod on the same time that are not necessarily used at the same time. (so there is pressure = aftertouch and tilt, for modulation per note).

      For a good player I don’t think release velocity will be too complex either, but at this point, it would be for me.

      This isn’t exactly a new standard for midi.
      There are few changes, as it is mostly covered by using different channels.
      The new standard mostly includes bunching a few channels together for a single instrument, with the support of a “global” midi channel in that bunch, that handles patch changes, volume and other such things that are not of the note independent type.
      So yes, it was a bit of a dissapointment. All this could already be done with the right bridge software.
      But as a standard, at least now it is recognized so that new products can be developed to handle it from the start.

  2. been waiting for 2+ years for mpe to be a unified standard, finally it’s here. now hoping the big wigs of the industry will come out with great hardware, the market for it is out there.

    1. At this point, it’s a mark against any polyphonic synth that gets introduced if it doesn’t support MPE.

      My understanding is that Moog and Dave Smith Instruments both have jaw-dropping MPE synths in the works, and that’s part of why they didn’t show at NAMM.

      1. i doubt it.
        Why would Dave Smith then have released the Rev-2 without it?
        This so called new standard is already supported, because it is a workaround, that is now called a standard.
        What it does, is that it uses midi multitimbrality and still only mono expression per channel.
        It is actually possible to play 90s sound modules with MPE, with this work-around. But it would require either setting up a “performance” with all parts having the same sound, and then a hardware that supports channel rotation (Linnstrument has that built in and Keith McMillen has their Midi Expander, but there are other hardware products that does this as well, and there is software that can act like a bridge and to this).

  3. Finally! Now I’m going to start saving up for a Linnstrument now that hardware synth designers will actually be implementing MPE.

  4. This is really great. Also there are rumors that moog is releasing a polysynth in the next year or so that will implement MPE. My linnstrument has a bright future ahead 😀

  5. The markets is now open for a reasonably priced MPE controller, Roli and Linn have excluded themselves from this race by price alone so far.

  6. Good to hear. Small inaccuracy: the basics of this have been present in MIDI since the beginning as MIDI Guitar Mode, which this is an augmentation of. It’s unfortunate that the need was thought to ignore its long legacy in the world of MIDI instruments. For example, my Prophet VS, built in 1986, supports independent expression per voice-channel, yet is not fully multitimbral. Likewise with a number of other early MIDI instruments the capabilities of which are all well known.

    1. Not necessarily.
      There is nothing in this so called new standard that says that the hardware has to support single channel polyphonic aftertouch.
      This is simply a method of using midi multitimbrality for polyphonic expression.
      Even a 90s sound module can support this form of MPE, if the user sets it upp correctly.

  7. We already have polyphonic aftertouch, yet there are very few instruments that have ever supported it (compared to those that don’t). Why is this going to be any different? Is there really a pent-up demand for “multi-dimensional” control? I would much rather see a new high-speed implementation of midi aimed at solving its two major fundamental problems – jitter and latency. I know there are solutions to these problems but they usually involve expensive extra hardware.

    1. probably the major reason so few instruments ever supported polyphonic aftertouch was the limited number of controllers that supported it, and the cost of making them.
      These new MPE controllers mostly rely on other types of playing surfaces compared to the typical piano styled keys, and because of that, it is much easier to implement and much much cheaper.

      When people start getting access to polyphonic expression, there will be a demand for it.
      And we have already started to see that.

      Keep in min that polyphonic expression also enables single note expression, without affecting other notes.
      To my ears independent bending of multiople notes is often not pleasing. But the ability to bend a single note while holding other notes, well that is appealing to me.
      But for aftertouch/pressure and tilt it also enables slight variations of the expression of each note, just like there would be variations in the expression on physical instruments that either can be played polyphonically by a single person or when notes are played polyphoically by having a number of players all playing their own individual notes. In that way it will sound less static.

      This actually isn’t much of a new standard.
      It is a workaround that the Midi standard organisation has accepted as a way to deal with this issue.
      It relies on midi multitimbrality, that you can find in many 90s sound modules even. One just has to set all the parts to play the same patch, and then one has polyphonic expression. And there has been software for years that have been able to handle this.

  8. Other than supporting multiple dimensions per note, how is this better than or different from old-school MIDI polyphonic aftertouch that dates back to the 1980s? (Or 1970s in the case of pre-MIDI poly pressure on the CS80?)

    Is it more efficient? Higher resolution? Lower latency? Reduced jitter?

    Will it be more widely supported in actually available (and affordable) controllers with traditional synth/piano-style keyboards? (Nothing against the Continuum or Seaboard but they’re not for everyone…)

    The Prophet ’08 (and some other DSI synths) as well as software synths like ES2 (Logic) and Animoog (iOS/pictured above) already respond to polyphonic aftertouch (and Animoog can also generate it.)

    Unfortunately there is a shortage of good poly pressure instruments. I have a CME Xkey 37 and a KMI QuNexus, but they are both small keyboards with minimal key travel. I also foolishly bought a VAXMIDI kit via kickstarter, but that turned out to have fatal design flaws – I don’t think anyone has been able to get the poly pressure to work properly, and most kits don’t even work as normal keyboards!!

    That being said, the QuNexus actually generates pressure and tilt, so it would be nice to have a standard that can accept multiple dimensions for controllers that can generate them

    1. As a Linnstrument owner I must say that while aftertouch (a thing that is either “off” for the first 95% of velocity or “on” for the last 5%) was neat and useful for a while given the limitations, it now feels clunky and not expressive/organic. I guess once you’ve crossed that bridge it’s hard to go back.

    2. KMI will soon start delivering the K Board Pro 4… and I expect that there might be a Pro 5 coming, some time after.

      But when it comes to regular keyboards with piano styled keys;
      Waxmidi and touchkeys are the only methods I know of, that would be cheaper than the old way of polyphonic aftertouch, and that would be too expensive. And only the touchkes support other polyphonic expression than aftertouch.

      But in my mind, we should probably free ourself from thinking that the most natural way to play synths, is on a piano styled keyboard.
      It was not chosen because it was the best way. it was chosen because that was what was around.
      I wish I could have been tought to play the Linnstrument. Because that layout seems promising. Although I have to say I was a bit dissapointed that I felt some scrubbing on my fingers when I tried to do slides on it. But it is not like guitars are finger friendly in the beginning.
      But with todays technology it is also possible to do controllers that are adopted to scales and key, that doesn’t have to rely on having chromatic layout.
      Once we get cheap enough Oled screens that they can be put in each pad/”key”, things could really change.

      It is not really any better, but it does offer both pressure/aftertouch, tilt, and pitchbend note indepent, for a more natural variation, or for using it at just one of the played notes. I guess it also supports release velocity.

      I’ve heard that the pressure sensitivity implementation of the Linnstrument responds better than many other types of aftertouch… But that would if true be construction related and not have to to with this standard.
      I haven’t actually played one, just felt it in a store.

      This standard will probably have a better spread than polyphonic aftertouch in the past, since the controllers to support it now can be much cheaper. Because they don’t have to be designed like traditional piano keys.
      And this standard is pretty much just an extension of multitibrality over midi. The same thing could be achieved on a 90s sound module if each part is set up to respond to a unique midi channel, and the patch is the same on all parts. But they also specified how it can be handled more smoothly by sending some information over one channel that would make changes for all channels.

      But it probably won’t be a universal standard supported by every new polyphonic synth (software or hardware) coming out. Just a wider selection than in the past.

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