Discover the  Roto-Chromatic Harmonica

"It's revolutionary!!"

"Fully chromatic
        in both melody and chords."

What it does
The music
How it works
Progress report


Where it's at

In a nutshell

About this site

The Roto-Chromatic Harmonica

In this introductory section you will get an overview of the features of this new invention as well as a brief look at its capabilities, its progress and the role of this website in its development and promotion.

Features of the Roto-Chromatic Harmonica

The Roto-Chromatic harmonica differs from existing harmonicas in several ways:

  • It plays chords - lots of chords!  It can play seven different chord types in all 12 keys.
    Namely:  major,  minor,  augmented,  diminished,  sus4th, flat-5th,  and  7th (triad version).
  • It is truly chromatic.  Melodies and chords can be played in all keys with similar patterns of hand motion and breathing for each key.
  • All notes are available either blowing or drawing, eliminating the need to reverse breath during a melodic phrase.
  • And of course, with all those chords, there is almost no limit to the ways a melody can be harmonized.

Diatonic players apply great skill in getting the notes they need via blow-bends, over-blows, special tunings, etc.  Chromatic players typically use a C-chromatic for only a few related keys and have several chromatics to cover all 12 keys.  With the Roto-Chromatic, melodies and chords can be played in any key with equal ease.  It is a whole new musical world to explore!

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In a Nutshell

When other pages of this site are complete they will explain the capabilities of the Roto-Chromatic in much more detail.  For the time being I hope that this very brief explanation helps.  It is hard to know where to start, but if you go over the material here a couple of times it should all fall into place.

The most basic feature is that each hole can connect to 4 possible reed chambers, the choice depending on the configuration of the control 'wheels' (see picture at top of page).  Each chamber has both a blow and a draw reed with the draw reed being tuned a tone higher.

The 4 reed chambers of the first hole have their blow reeds tuned to G, G#, A and A#, and their corresponding draw reeds tuned to A, A#, B and C.  The 4 reed chambers of the second hole are all 4 semitones higher than those of the first hole, a pattern that continues on up the harmonica. 

The diagrams are color-coded to show which wheel has control of which hole.  The gray wheel controls the slide, which blocks the highest note for each hole when in the left position, and the lowest note when in the right position.  Take some time to look at these example configurations.

Here is a brief discussion of each diagram:

  • Diagram 1 shows the wheels configured to produce a C chord when blowing.  Notice the highest notes for each hole are gray, indicating that the slide is in the left position. 
  • Diagram 2 shows the wheels configured to produce a 'Dsus4' chord when the player is drawing.  Notice that only the green wheel had to be moved from the previous diagram.
  • Diagram 3 shows that the slide has been moved to the right position by turning the gray wheel.  (Notice that it does not matter which way this wheel is turned.)  The chord is an A#dim when blowing.
  • Diagram 4 shows an A#7 (triad version) chord when drawing.  This triad, A#-D-G# (Bb-D-Ab), is not a full 7th chord but for convenience it will be referred to as a 7th here.

Going over these four examples should provide a good idea of what is possible, but for the record, some important features and facts are listed here:

  • There are 46 configurations possible (54 but 8 where moving the slide has no effect).
  • Each wheel only needs to turn one 'notch' to move directly to its new position.
  • This means that any of the 46 configurations of the wheels can be reached directly from any other with a one 'notch' turn in the appropriate wheels.
  • If the controlling hand is moving to the right it can rotate a wheel clockwise by engaging it on top with a finger, or it can rotate it counter-clockwise by engaging it on the bottom with the thumb.  A finger or thumb can move 2 wheels at once since they are about 1/4" apart.
  • The gray wheel will alternate the slide between left and right positions regardless of which direction it is turned, so if you run out of fingers it can be turned along with the blue wheel.
  • This means that any configuration can be reached from any other with a 1/2" motion of one hand, using only 2 fingers and a thumb. (amazing but true - see discussion below)
  • Chords can be changed while playing, allowing a note to be accompanied with a second moving voice or harmony.  For example a C note can be held while the note below changes from G to A to Bb.  With tongue blocking you can even play 'Chopsticks', in all 12 keys!  (if you want)
  • Although there are 46 configurations, or 'absolute' patterns, there are only 7 'relative' patterns, corresponding to the 7 types of chords. 
  • Including both blow and draw there are 92 chords, but some appear twice leaving only 76 unique chords.  There are 4 augmented chords and 12 each of the other types.
  • Chord types are: major, minor, augmented, diminished, sus4th, flat-5th, and 7th (triad).
  • For any key all chords and harmonies, in that key, are available without moving the slide.  And of course chromatic melodies can be played without moving the slide.

To understand how the hand is used to change configurations consider the example of changing from the A#dim in diagram 3, to the A#7 in diagram 4.  Engage the blue wheel with the thumb and the orange and green wheels with the fingers (one finger can turn both).  Then move the hand to the left one 'notch'.  Or, alternatively, engage the blue wheel with the fingers, the orange and green with the thumb, and move the hand to the right.  In most situations (85%) the required manipulation can be achieved moving in either direction. 

Because the gray wheel will 'toggle' the slide, no matter which way it is rotated, it can be turned by whichever digit is available to turn the blue wheel.  Meaning no extra finger is required for this extra wheel!

By now you can see that you can play any chromatic melody whatsoever, in any key,  harmonized in (almost) any way you might choose.  There is a lot of fun waiting to be had. 

This is about as much as I can squeeze into a nutshell.  As the website is developed you will be able to get more detailed explanations (pictures, diagrams etc.) of how it works and what it can do.  Check back every few weeks, or ask to be put on my mailing list and be alerted of updates.

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About this Website (site under construction - your patience is appreciated)

This website is dedicated to explaining the 'how's and 'why's of this versatile new invention.  Here you will find out how it works, how to play it, the music it can make, its origins, and keep up to date with its ongoing development.

The essential feature of this invention is the rotatable 'diverters' - round cup-shaped valves that direct the player's breath into one of three directions.  This breakthrough idea occurred in a garage workshop in northwest Calgary in late 2008, but the project began much earlier on a loading dock in Vancouver.  As this website unfolds you will be able to find out how it started and get the full explanation of how it works, complete with pictures and diagrams. 

This website will eventually include instructions for beginners, showing how to play a simple scale and chords.  And there will also be a 'quick start' section where you will be able to jump right in and learn how to play a simple tune, in all 12 keys.

Please contact me with any questions or comments.  Doug at

Note: Even though the site is still under construction I will gladly try and answer any questions you have.  All questions are welcome as they will guide me in my efforts to create a useful and interesting website.

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