Note there is an update of this post coming up soon (based on feedback received for improvement)

The Isomorphic (ISO) English Concertina (EC) project aims to investigate an alternative keyboard layout for the English concertina. The goal is to take into account the EC’s most powerful features alongside the most popular/proven isomorphic layout employed in concertinas – the Wicki-Hayden layout.

I am very grateful for any feedback/ideas/comments you may have :).

I have added all references in-line, but please let me know if any additional reference was missed or should be added

EC Features

The following are the EC’s features to be employed on the ISO EC with the rationale for their use. These features are in fact what enable a feature-complete isomorphic layout implementation: said otherwise I believe the EC is especially well suited to for an isomorphic keyboard layout.

Alternating Hands Layout

This is the most unique and powerful feature of the EC. This feature is specially important for allowing for a small portable instrument, or conversely for fitting a larger number of buttons for the same size instrument (e.g. to cover a larger range or in our case for the implementation of a feature-complete isomorphic layout).

For the size/portability of ECs it is entertaining to research dimensions and weight of vintage EC concertinas compared to others (or new English hybrids). Both the use of alternating hands layout and proper concertina reed-pans are key factors in enabling smaller sizes / larger button count / larger ranges.

Listing the alternating hands advantages:

  • Better left-hand (LH) / right-hand (RH) keyboard weight distribution.
    • Compared to LH-bass / RH-treble systems where LH-bass reeds are required to be much larger/heavier to accomodate lower pitches.
  • Avoids LH / RH half-octave overlaps.
    • Compared to LH-bass / RH-treble where it is recommended to have range overlap to avoid switching hands in-play (often times treble comes down to G3 or less, while bass comes up to C4)
  • Less RH / LH bias for all players: more inclusive.
    • Compared to bass-LH / Treble-RH systems which tend to be more RH-centric.

  • RH on lines, LH on blanks of musical score: powerful mnemonic employed for the EC.

  • Allows for smaller size or larger # of buttons: for feature-complete ISO EC layout.

Unisonoric reed-pans/banks

Unisonoric sound production is favoured for allowing chromatic regular layouts compared to bisonoric diatonic layouts (which tend to be limited to a few scales per instrument).

  • Allows for ease of reading musical scores

  • Allows for regular phrasing independence from bellows direction.

Isomorphic Layout

Isomorphic layouts for musical instruments (Most noteworthy examples are the chromatic button accordion and the Hayden duet concertina have many advantages and although there are many layouts devised for musical instruments : the isomorphic layout designed, manufactured and proven for the concertina is the wicki-hayden layout.

For the ISO EC project, The Wicki-hayden layout was adapted to work alongside the EC constraints above. Currently a 56 button complete layout is shown (scales and chords adapted from the musixpro wiki), although a 48 version can exist as well with an accordingly reduced range.

ISO EC layout intervals

The full (56 button) ISO EC layout is shown below with all semitone intervals annotated and color coded.

Keyboard Layout Intervals

ISO EC keyboard layout dimensions

The keyboard layout with annotated dimensions and intervals is shown below.

Keyboard Layout

Also you can download a true-to-scale Keyboard layout PDF for print and experimentation.

ISO EC Scales Fingering Patterns

The fingering patterns for all major and minor scales are shown below.

Major and Minor Scales

Also you can download a true-to-scale Major and Minor scales PDF for print and experimentation.

The fingering patterns for all blues and pentatonic scales are shown below.

Blues and Pentatonic Scales

Also you can download a true-to-scale Blues and Pentatonic scales PDF for print and experimentation.

ISO EC Chords Fingering Patterns

The fingering patterns for all major & minor chords are shown below.

Major and Minor Chords

Also you can download a true-to-scale Major and Minor chords PDF for print and experimentation.

The fingering patterns for all augmented & diminished chords are shown below.

Augmented and Diminished Chords

Also you can download a true-to-scale Augmented and Diminished chords PDF for print and experimentation.

The fingering patterns for all flat5 & sus4 chords are shown below.

Flat5 and Sus4 Chords

Also you can download a true-to-scale Flat5 and Sus4 chords PDF for print and experimentation.

Lastly but probably most practical, you can download a complete PDF with all the resources here: ISO EC System

Next Steps

This is a very long time-frame project (I don’t have much time, only a bit after-work sometimes), but my thoughts on next steps are along the lines of:

  • Community feedback / interest (is the idea any good? is it worth spending nights on? :))

Then, based on above merit, baby-steps iterations towards:

  • Getting some sort of non-functional to-scale proof of concept

Then if the idea still holds value, using an old concertina to try to repair/devise:

  • A functional prototype.

Although I am an engineer and have been working on this idea for some time – as I am really interested in squeezeboxes (accordions and concertinas) – my experience in this area is very limited. Nevertheless, I hope you found some of these thoughts interesting ;).



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