Playing a virtual concertina on your PC

Inspired by far too much Sea of Thieves during COVID, and also TikTok sea shanties.

How to

Download and install Virtual MIDI Piano Keyboard (VMPK) This software lets you play your computer keyboard like an instrument.

Download the raw keyboard layout concertina-raw.xml from this Github repository.

Configure VMPK to use the raw keyboard layout and set it to "raw" mode.

Pick an instrument in VMPK. "Accordion" or "Reed Organ" sound concertina-ish.

Press keyboard keys and notes should play. A simple major scale starting with middle C is:

N M , H J K L U

Caveats / limitations

Windows only. The keyboard layouts would have to be re-generated for other operating systems.
Doesn't simulate moving the bellows, or whatever it's called when you pull/push an accordion.
Most consumer computer keyboards will "lock" when too many keys are pressed at once, meaning certain chords may be impossible. More expensive mechanical or gaming keyboards don't have this problem.

Concertina layout

There seem to be many different types of Concertina. Below is the layout used here, I believe it's called a "duet concertina." The left hand has basically the same layout as the right, but transposed down with some overlap. (Images of duet concertinas here: https://www.concertina.info/tina.faq/conc-typ.htm)

Left hand (bass)

C3 is left shift, F3 is capslock, Bb3 is Tab, F4 is 1.

       F4    G4    A4    B4
    Bb3  [C4]   D4    E4    F#4   G#4
       F3    G3    A3    B3    C#4   D#4
          C3    D3    E3    F#3   G#3

Right hand (treble, melody)

C4 is N, F4 is H, Bb4 is U, F5 is 7, and Bb5 is F5

    Bb5   C6    D6
       F5    G5    A5    B5    C#6
    Bb4   C5    D5    E5    F#5   G#5
       F4    G4    A4    B4    C#5   D#5
         [C4]   D4    E4    F#4   G#4

Resources

Based on these resources, because I do not know much about music or musical instruments:

Misc

C4 = middle C

B->C and E->F are half-steps (no sharp/flat between them)

cspotcode/virtual-concertina