24-Tone Equal Temperament (24-Tet) With An OB-6 Synthesizer

This video, via Kris Lennox, explores using a 24-Tone equal-tempered scale on the Dave Smith Instruments OB-6 synthesizer.

“One of the greatest strengths of synthesis over acoustic is the ability to program alternate tuning systems,” notes Lennox. “Not all hardware synths can do this, though. It is the preserve of only a few – and one of the strengths of DSI instruments and the OB6 i.e. creating and installing your own tuning system on the synth.”

The 24-Tone Equal Tempered scale (aka quarter-tone or 24-TET scale) contains all the notes of the standard 12-note scale, but adds 12 more notes in between. The additional pitches open up a huge variety of new harmonic possibilities, allowing for both traditional harmonies and ‘alien’ ones.

Acoustic instruments can be designed or adapted for use with 24-Tone scales or other tunings. But synths that offer microtonal support make it easy to explore a range of possibilities that would be impractical with traditional instruments.

Here’s what Lennox has to say about the video:

“Quite a shame to think – given the technology we have – the majority of contemporary composers aren’t exploring/creating their own tonal systems.

Most universities/conservatoires only briefly mention alternate tuning systems as part of coursework. If it is mentioned at all. Such a waste. Given there are an infinite number of notes between any two notes, every human being on the planet could have their own system of harmony.

Then again, this kind of material is and likely always will be esoteric.

PS actually seeing what I’m doing is, I trust, better than simply hearing a computer play back audio samples. Hearing the scale on its own, followed by some chords at the end of the video is handy i.e. both melodic and harmonic illustrations. Retraining the mind to perform 12-tone music on a 24-tone treatment of the keyboard is refreshing/slightly mind-warping!

Any pianist feeling life is becoming a little easy/predictable should try it.

If you’ve worked with alternate tunings, leave a comment and share your experience!

16 thoughts on “24-Tone Equal Temperament (24-Tet) With An OB-6 Synthesizer

    1. Yeah it does. DSI has been building in top notch tuning support to all their instruments for several years. The OB-6, Rev-2, Prophet-12 and Prophet-6 all support the MIDI Tuning Standard. So, 0.006 cent resolution and you can independently retune all 128 MIDI keys to any pitch you want in any order.

  1. playing non 12 tone stuff on a usual keyboard makes my brain hurt
    but if I have a keyboard with only white keys/every key looks the same it works much better …

    1. I agree . However, what keyboards or controllers are there to play microtuning scales? Not many. You almost have to create your own controller. In hardware it is rather difficult, using tablets and software like Lemur it lacks velocity and pressure. It is rather difficult to work with microtonality, but it’s possible.

  2. yes, it is.
    but some statements in this article are completely pretentious.

    “Quite a shame to think – given the technology we have – the majority of contemporary composers aren’t exploring/creating their own tonal systems.”


    the interesting stuff are the world music scales and not the made up crap imho

    some of the “chords” he is playing with the arabian scale, I dont recognize these as chords – its more a drone or cluster of frequencies – but I wouldn’t call that a “chord”

    1. Sorry, but dismissing the work of all contemporary composers is what comes off as pretentious.

      Also, everything you say about ‘arabian’ scales and chords is factually incorrect. Learn a little about music theory and world music and open your ears a bit!

        1. Learn some music history!

          “Bach did not use equal temperament. In fact, in his day there was no way to tune strings to equal temperament, because there were no devices to measure frequency. They had no scientific method to achieve real equal-ness; they could only approximate.”


          The tuning system that Bach used would be considered microtonal by today’s standards. 12 tone equal temperament wasn’t really widely adopted until about 100 years ago.

          There’s lots of classical music that used what most people would consider microtonal, not even considering the classical music of non-western traditions, which have billions of fans.

          The idea that things that sound ‘funny’ to your ears are somehow inferior is simply ignorant of reality. You just like what you are used to.

          1. gee, those tunings aren’t that far away from each other,
            I think of it as minor variances;
            its not Wendy Carlos sailing away with the pitch in alpha scale or something,
            that is radical different 😉

  3. Very cool. Personally I find it more useful to retune select notes away from equal temperament. For instance, one of my favorite scales takes a natural minor and flattens the 2nd and sharpens the 6th by a 1/4 tone.

  4. I mean, the goal of this video is to let us ear the pitch differences on that temperament and the sound used has a ton of reverb which actually tend to hide pitch informations… “yea but sounds better!”

  5. Kris, the person who is playing the OB6 in the video here. Someone emailed me RE the piece appearing on this site – and the comments.

    Firstly – max – I’d have appreciated you simply writing in the comments for the video RE your thoughts.

    To your points:

    1) Not too long ago I asked my publishers RE data pertaining to composers they represent using tuning systems other than 12-tone. The reply was 1.2% i.e. 98.8% of their representation works within the 12-tone system. Assuming this figure is representative of all contemporary composers, the statement made RE the majority was a statistical assertion, not a biased opinion. Given I also write tonally, it is not an either/or statement, but rather, an observation on how the infinite tuning possibilities we have are not yet being harnessed/explored aside from a very few. However, I’m sure I also mentioned the nature of alternate tuning systems likely remaining a very small niche.

    2) The technical definition of a chord is ‘more than two notes sounded simultaneously’. Nowhere does the definition state any relative dissonance/consonance (or how ‘pleasing’ someone finds the sound to be) as a determining factor in whether said sounds qualify as ‘chords’. I think you should possibly go back a good few decades and have a look at Cowell etc. Simultaneously sounding C/C#/D is a chord; perceived dissonance plays no determining factor.

    3) Which Arabian scale are you referring to? There are many. Specifically, I wasn’t using any known/etablished Arabian scale, but rather, a mathematically-derived scale from one of the 735,471 sixteen-note scales of the 24-TET system. I’ve (literally) wrote the book on and formalised the entire 24-TET system. The included video was a very casual introduction for any curious listeners; aforementioned material RE 24-TET will be released soon. Part of the fellowship/post-doctoral research I undertook over a decade ago focused on creating working mathematical models for any n-note alternate tuning system, and methods of calculating relative dissonance within any such system.

    4) Reverb was added to give the music some context, timbrally, and how it may sound within a musical framework.

    5) All scales are ‘made up’. The exception being, of course, the harmonic series.

    The thoughts you are fighting with are ones I had myself when I was around 10 or 12, so I do appreciate where you are coming from. And I’m sure you appreciate my freely sharing of the material with the general public.

    My speaking casually on YT is more a case of audience-aware. No need to impress followers with a list of credentials etc.

    Again, I’m sure you meant well, but please learn the meaning of basic concepts (i.e. ‘chord’) before replying to points when the person making those points is the individual who has, as previously stated, literally formalised the entire system.

    Again – if there are any points, do please raise them on YT as I don’t visit this site and was not aware of the video being posted here.

    By all means discuss the material – but discussing material should not be confused with making crude judgements/character assessments based on decontextualized sentences.

    PS if the subject is one you have a true interest in, I’d recommend you have a look at the likes of the Journal of Mathematics and Music, where articles on 24-TET occasionally appear.

    All best

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