Modern Microtonal Electronic Instruments

In this video, composer and synthesist Dolores Catherino shares her take on a selection of modern microtonal electronic instruments, including:

  • Tonal Plexus
  • Roli Seaboard
  • Continuum Fingerboard
  • Microzone U-648

Catherino suggests that modern microtonal electronic instruments free us to move beyond ‘low-resolution’ 12-notes/octave music making.

She describes this as a transition from monochromatic system that is easily captured with black and white music notation, to a polychromatic system, where notes have ‘colors’ that are more easily captured with full-color music notation.

Here’s a performance example of Catherino’s work, Heterodyne Horizon: 

Heterodyne Horizon uses an ‘auditory resolution’ of 106 note/octave, vs the comparatively ‘low res’ 12 notes/octave. This allows her to use changing of the ‘color’ of chords as a compositional element.

And, as she notes in her discussion above, her performance highlights how the microtonal capabilities of these new electronic instruments challenge us to listen in new ways, and also to expand our language for notation and discussion of music.

35 thoughts on “Modern Microtonal Electronic Instruments

  1. Terrific. Fully enjoyed her hype-free explanations of the musical pros and cons of each controller. That Tonal Plexus with the control module looks like the business.

    I’d never heard of her or her music so thanks for both @synthhead.

    1. Woah! I’d seen the emergence of some of these instruments here and there. At first they seemed very strange like a keyboard halfway melted or bathed in a layer of heavy chocolate syrup. These instruments give the appearance of some alien technology being given as a gift to the human race. Very unique and beautiful sounds for sure.

      I can definitely see the younger generation embracing this new technology as they begin to master the sounds. This seems like the revolution of the future of music. I always admire the excitement of musicians as they describe how music makes them feel, I can sense the physical and spiritual connection they must feel while playing.

      I look forward to hearing more as these instruments are further developed and are refined.

      Keep up the great work and sound design! 🙂

    1. Well.. Not really. That I know of you can only get monophonic pitch bend with a pitch wheel. Wouldn’t this give you polyphonic “pitch bend”? Also consider a pedal tone: A C root while bending the melody wouldn’t be possible outside of possible split-type parameters/programming I am as of yet not aware of. Sure you could use two controllers… Also consider the difference in tactile feedback: a pitch wheel is a specific motion device with some resistance while this is a different paradigm altogether. These are just counter suggestions. The caveat is that I’m a relative noob to keyboards, MIDI and ilk.

    2. Dr.Nemmo

      Your comments suggest that you’re unfamiliar with how MIDI works, how microtonality works and how pitch bend works on MIDI keyboards.

      There’s a lot of cool work being done with new MIDI controllers that’s worth learning about.

      1. @Hexspa Almost. Pitch bend is a channel level control; it will bend all notes on a given MIDI channel the same amount.

        “Nothing that the proper use of the pitchwheel can’t emulate.” is the right idea but misses the mark. Indeed, all of these instruments probably use pitch bend to make their microtonal magic happen (at least with regard to sending MIDI commands). Thing is, a “yellow C” is going to be a different amount of pitchbend than an “orange G” so there’s no way to reduce it to “proper use of pitch bend” unless you’re playing monophonically and even that is pretty optimistic within the reality of playing from note to note. Instead, with a controller like this each key press goes out a different MIDI channel and any amount of pitch movement from standard MIDI tuning is represented as channel pitchbend. The device receiving the MIDI has to know what to do with all of that stuff. Some require you to an explicit multi-timbral set up with the same sound on each channel. Some, like iOS’ Thumbjam can be put into a mode that essentially a version of mono-phonic round-robin Omni.

        Check out

        The other way, at least for an instrument that doesn’t do real time per-note bends (like the Tonal Plexus), is to use MTS ( or Scala Files ( In that case, the sound making device needs to support those standards.

    3. pitch wheel is some of the best emulation of VCO drift in my experience too haha.. whether on monophonic or polyphonic passages, can reaally surprisingly give all that subtlety we end up looking for in ever-more expensive gear options ha.

      old synth chords and lines like in Vangelis are to a certain extend the result of analog LFOs and EGs sure, but he is riding that pitch wheel just as much to give the right bloom to his notes. It’s a beautiful technique! The next KMI pro board will be an interesting tool for the same idea too so I’m excited for that.

    1. It’s a great video and rare, exceptional and unique to expertly compare the advantages of each of these different keyboards. I think she is the only person in the world today who owns all of these, and she is also clearly to anyone with ears an expert and expressive composer.

      1. Indeed. Happily, I missed the first comment. I’m usually only interested in microtonal things for the 5 minutes I’m watching Harry Partch or similar. Or maybe the 15 minutes I’m reading some impassioned music historian’s pitch on why we’ve ruined music with the man’s 12 step compromise. Instead, Catherino got me incredibly interested because she made BEAUTIFUL FUCKING MUSIC happen simply by combining a few notes, expertly. Or should I say colors? There are moments in her music that sound like My Blood Valentine to me—’just enough’ notes, sublimely beautiful yet somehow full of tension.

  2. There is a vagueness in the ‘shapes and colours’ i would hope for more..
    Anyway i didn’t get the whole thing about limitations in recording formats and speakers! As far as i know many speakers can go up to 30-40k plus sampling rates up to amd more than 192k..

    btw i believe you can buy the continuum without the keyboard layout nad program it however you like…

    1. Surely you’ve experienced how your body can sense sounds outside of your range of hearing. Infrasound – sounds below the 20 hz, can easily be sensed by your body, for example.

      Some argue that these infrasonic and ultrasonic sounds – which are filtered out in creating digital recordings – are part of what distinguishes original sounds from their reproductions.

      1. Yep. I’m a 24/44.1 kind of guy (and 24 only because I’m lazy) but if we’re talking about sets of overtones we don’t normally hear, I’ll reserve judgement.

  3. Regarding her mention of the limitations of sample resolution. Why not use an analog source? Do these controllers not have a midi out, would that require a re-work of midi’s signal resolution? If that was an issue, why haven’t manufacturers incorporated an analog source into one of these boards?

    1. That’s what I want to know. A buchla system or music easel is more expressive to my ears. Simple controls over complex sounds

  4. Amazing that with all the hype around the seaboard the resolution would be so much worse than one of the first electronic instruments, the theremin! I think the realities of trying to play an instrument like the tonal plexus render it nearly useless as a true “instrument” but rather an interesting tool with which to compose, but her system of coloring notes is really well thought out. Fascinating nevertheless!

    1. It’s interesting and she brought it up: there’s a trade off between expressiveness and playability. For my novice ears, I had to rewind several times to hear the difference (1/4 tones) in the very last slow example she did. And even then I might have just been telling myself I heard it!

      Seems to me the sweet spot for something like the Roli would be to quantize different horizontal regions. Like, the top 1/4 of the keys are pretty much fixed like keyboard. Further toward the bottom you go, the more ‘freedom’ there is between the notes with the very bottom being a flat continuous ribbon.

      The Tonal Plexus maker has a pretty interesting paper about, well, a lot but quite a bit is about this intersection and previous attempts at getting back to microtonal instruments.

    2. Wendy/Walter Carlos made lots of use of pitch drift and non-equal-tempered scale that became options on 80s digital synths too. For the average person pursuing these sounds, It’s not just about analog v. digital, or chasing the extremes of sample rate fidelity, but finding gear that gives you a reasonable-enough grasp of the tuning of the instrument to intelligently get between the standard tunings and find a fertile sound.

      (oops sorry meant to reply to the previous comment with this, not yours)

  5. I think microtonality is an interesting branch of music but call me deaf, stupid or under educated ( anything you like at will ) I think it is not useful outside of some special sound effects.

    Some says that 12 notes are too limiting for them, yet however they are far from reaching the possibilities of those 12 notes. Create beautiful compositions in 12 notes, then I could accept if you say ‘I have grown out the 12 notes, and I need more expression space to go further’.

    Most of the people strive for the best synths but an disputably exceptional classical melody sounds remarkably even on the cheapest device and can be enjoyed by a broad audience not just for the super educated 1%. And those are yes, only in 12 notes ‘low res’.

    1. microtonal is just another way for people to feel superior about their knowledge and how its use can elevate the educated listener or performer out of the common trappings of everyday music of the vernacular. not unlike polyrhythms, modular, analogue and god knows what else, its just about trying to be different. like when an indie kid discovers the velvet underground for the first time and thinks because none of his peers have done so his enlightenment gives some new quality of authenticity.

      a large pinch of salt required

      1. Whiteblob

        You do know that the majority of the musicians in the world have traditionally not used 12-tone equal-tempered tuning, don’t you? Are you saying they’re all trying to act superior?

        1. Yes, for example Indian music has 24 notes (or 22 sorry for being such under educated, but cannot remember exactly for now) but not over 100 or infinite. Yet one can still “emulate” the original melodies on 12 notes though.

      2. Did you actually listen to any of the music she’s made? She is, to my eyes/ears anyway, not trying to be or do any of the things you described. Instead, she made some sonic magic happen by having access to and an appreciation for the ‘colors’ in between the 12 western steps.

      3. You know what isn’t fixed to the 12 notes of the western scale: the human voice. Sure, we all appreciate when some one sings ‘on key’ but our groins and hearts react to people who flirt with it: billy holiday, mick jagger, lou reed, kim gordon… All, ahem, ‘microtonal’ singers that move millions of people. Sure, the Maroon 5 guy ‘can sing’ but Bob Dylan can sell out stadiums 40 years into his career. Good luck, maroon dude.

        How about bending guitar notes? Or slide guitar? Or the original THX sound? Or the way an upright bass misses the ‘root note’ so often but just “feels right”? Attempting to reduce all of these things to wannabeism (which, fair enough, may indeed be a motivation for some) is kinda missing the point.

    2. “I think microtonality is an interesting branch of music but call me deaf, stupid or under educated ( anything you like at will ) I think it is not useful outside of some special sound effects.”

      Let’s just say your perspective is a little euro-centric.

      If you listen to music from India, China, the Arab world, it’s what we call microtonal.

      So, yeah, microtonal systems are useful for more than ‘special sound effects’.

      If you want to open your ears in a pretty painless way, check out the music of Robert Rich. It’s very electronic, but also fairly consistently microtonal.

  6. There is no “superiority” in freely moving between pitches and tunes. That is pretty natural standard. An afghane shepherd will never think about that playing his flute. Pitch modulation on polyphonic aftertouch keyboards like the ensoniq asr-10 sampler had should be pretty standard. After mine broke is was really disappointed that so many other keys and synths do not offer that. Holding a chord while pressing the keys differently on some too high pitched and aliasing artefact heavy samples brought some of the most unusual results to me. Man, how do i miss these “simple” things in todays samplers and synths.

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