A “Melodic Flow” like key mapping to jam with a chord progression

So imagine you have selected a chord progression and a key in scaler, and want to play along with it and have no theory knowledge. Imagine a scale-key lock that does the following.

As each chord in the progression is played, the mapping of the midi changes such that the root note of the chord is put on a particular white key ( let’s say C3, for example), the next highest note in the chord is placed on the next white key (D3), the third note on the next white key, until the chord notes are exhausted. The remaining white keys in the octave are then allocated the remaining notes in the selected key.

On the black keys, you map the chords in the following way. The most recent or ‘current’ chord is mapped to the first black key (C3 sharp). But each time a chord is played, it shuffles down the black keys. So the prior chord in the progression is on D3 sharp, the one before that on F3 sharp, and so on. Hence the 5 black notes in the octave play the current chord and the four prior to it.

Now imagine that mapping above is repeated up and down the octaves of the keyboard, with all the mappings simply shifted by an octave as they change, so the mapping is not restricted to any specific subset of the keyboard.

As your chord progression plays, you can now jam along knowing that you will always be in key, have quick access to the recent chords on the black keys, and knowledge of how the white keys will relate to the chord.

If you want, you can now program arpeggios, melodies, or whatever as midi input in your DAW and then change the basic chord progression and your “solo” will follow.

I have been able to set up something very similar to this using Scaler a plugin called Melodic Flow and some midi utilities in Cubase. But it takes a lot of work and sending of transformed midi between tracks. Would be great if Scaler could do the work.

Finally: you might want one instance of Scaler to deal with and play the chord progression, and another to deal with the midi remapping I have described here so you can jam along with it. It would be great to be able to link instances of Scaler for this purpose with changes in the chord progression reflected in both instances in real time. I made a request for that linking of multiple instances a while ago.


Hi Barza,
Unless I am misreading you most of what you are describing is already in scaler. Have you played with Keys Lock and Chord Notes and Chord Extensions profile?
Also you can sync multiple instances of Scaler.
The black keys ‘recent chords’ idea is interesting. Thanks for feedback.

Davide - thanks very much for the reply.

The problem with the existing chordkeys/extensions key lock is that the variation of the key mapping as the chords are played only applies to two octaves of the keyboard, so you can’t go very far up and down before behaviour of the mapping reverts to being static.

As for syncing multiple instances of scaler, I believe this is static in the sense that it does not mirror the state of Scaler in real time. So every time I changed a chord my progression in one ‘master’ instance of Scaler i would have to resync all the “slave” instances. That is unless the behaviour has changed since 2.2 (I’ll check!). It would be great to be able to link your Scaler instances so certain changes propagate to all instances automatically as they are made.

As it stands, the black keys are simply not used once the chord notes/extensions key lock is turned on. So having these available to play chords (even if it was a static set, say the first five of the progression) would be useful. I personally think the idea of the first black key always playing the ‘current’ chord works much better, hence my idea about having the last 5 chords simply shuffling along the black notes as they are played.

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You are right @barza and they are problems. Problems that will be mitigated by a redesign of the UX to accomodate all of the features in a less limiting way. As a composer and producer who uses scaler daily across a wide range of projects I constantly run into ‘dead ends’
Our priority as a team is to eliminate those dead ends which would indeed encompass everything you have suggested. Stay tuned and thanks for feedback…

Good to hear - Scaler is just a great product so keep up the good work in the knowledge that there are a lot of appreciative users out there!

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Hi Davide

I have been thinking about this and can’t entirely see how the limitations of Scaler I describe above are generated by the design of the UI. Of course, there are probably inter-relations between function and UI developers like yourself are much better aware of than I. But at a first glance, I can’t see how the key mapping scheme I suggested above would be prevented by the UI. The keyboard at the top of the screen might not show all of the remapping going on for every key that is pressed on the keyboard, but I am pretty sure users could live with that. If there was simply another option added in the list of key-lock functions that worked as I described, it could be accommodated in the existing UI.

I also don’t think real-time sync between instances of Scaler is obviously a UI issue.


Just to be clear, our efforts are best focussed on moving forward and creating a product that works better and more intuitively for more people whilst incorporating many user request. Our aim is to enable more people to make music, so I don’t want more focus on scaler in its current iteration, certainly not where it takes focus off our future roadmap.


So it is not the UI per se that precludes adding the key-lock design I suggested. It is the more general desire to re-design the UI to allow for more features in general to be added, and the resource constraints in doing that. Fair enough.

So glad to see this conversation taking place and thank you barza for bringing up this subject, I so agree.
So much enjoying Scaler and I too love jamming in real-time with tonality assistance, been doing it forever.

In order to straighten out my notes I use either the Hotz Translator software or the scale midi effect in Ableton.
I typically pre program scale or chord note changes to fit my arrangements and then have them sequenced using DAW program changes, note sends or using a midi footswitch. Typically the black and white keys are separated using Virtual Midi Controller and that gives me a wider variety of valid (or sometimes invalid) notes to play with.
A lot of patching and tweaking goes into preparing the system for an enjoyable and creative real-time jamming performance, but the effort is well worth it.
I use different controllers for playing, EWI, Hotz Box, Machine, or a midi keyboard controller. For further expression also a midi footswitch and a couple of CC pedals. That and a variety of choice, responsive software instruments completes the pretty picture.

Scaler should be able to do all this and more.
(Making sure the correct notes are always played through, changing the scales or chord notes while following the chord progression, suggesting and sequencing scales or chord notes that are suitable for playing, eliminating double notes, and positioning or shifting the next scale change notes in proximity to where the last note was played.)

I am so looking forward to this happening and I am sure others will benefit too.
Scaler is allowing many people to actually become composers or better composers, with this feature they will also realize that they can play, jam, improvise, invent and express themselves.

If you build it they will come. Thank you.

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Thanks for the feedback and welcome to the forum. We have built in and they are coming! Agreed there is much more work to do and you angle in interesting.

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I can’t agree more on adding jamming features, as actually I love way more jamming than composing

Hi Davide. Scaler goes from strength to strength with each update, and I use it plenty. However, I notice the key mapping features haven’t changed much if at all in recent iterations. Are changes going anything like the direction suggested above at all likely in the next year or so. Just wondering if building more flexibility into the key mapping was explicitly on your roadmap. Thanks and happy new year!

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Happy new year to you too Barza. Yes indeed we are looking at expanding this section with our next major iteration. Looking for more flexibility and adjusting the way it works. This is an important part of scaler.

Thanks Davide, that is good news. Can you give us any hints on when the next major iteration is planned?

Can I also ask about real time sync of multiple scaler instances. I quite frequently find myself working with multiple instances of scaler; for example, I might have one instance generating block chords for one instrument and another generating melodies for a different instrument using one of the performance phrases. Having to manually resync them if I change the chord progression I want them both to use is a pain. It would be great if you could set it up so that some elements were replicated across those multiple instances in real time. Is this possible and on the roadmap?

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Yes possible, yes on the roadmap and yes planned for 22!

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There is another keyboard mapping scheme I have been playing with and finding useful which you might want to consider implementing (or including within the scope of how the user could flexibly remap the keyboard).

You choose a key, scale and chord progression in scaler. The white keys are mapped to the scale. As the chords play, the black keys are mapped to the chord notes from lowest to highest.

This is fun to jam with, as by playing the black notes all together you get the current chord, you can play very safe melodies just sticking with the black notes, or use the scale notes on the white keys. This is also useful to program melodies in midi, as you can put a melody together using combinations of scale notes and chord notes and then see how they work as you change the key, scale and chord progression.


Actually thats really cool if you can then switch the scale live, so you play the white keys in scale lock, switch scales via a keyswitch all the while whilst using the black keys for chord notes and extensions. I like it thanks.

Impressive set-up. Thanks for posting about it.

another option could be to leave the chord notes on the white keys. just map each chord note to your scale of choice to play live. so every time you play a different chord note, scaler locks into the scale you chose for that specific chord note. that way you dont have to go back and forth from white key to black key to change scale and chords when you can just do it with one note on your midi keyboard.