[David Hart]

That’s a beautiful-looking thing.

For what it’s worth, my wish-list for the ultimate melodica-type instrument would be roughly as follows:
– Available in 6-row button format (ideally including Janko layout, which is a whole lot more intuitive than the C system or B system, even if it does sacrifice some of the compactness – and I’ve always been baffled by why only the Serbians have the foresight to insist that their button accordions have 6 rows, thus allowing you to play any note with either a finger or the thumb without having to bunch your hand up)
– Equipped with two sets of reeds tuned an octave apart such that you can switch smoothly and gradually, or instantaneously, between low, low+high and high
– Fitted with a rigid but repositionable gooseneck mouthpiece like the Hammond 44 (but less breakable)
– Playable on both blow and draw
– Equipped with wah-wah grille as MelodicaMe suggests
– Equipped with some system to hold a high note as a drone without having to keep your pinkie on the key, and thus imitate the sound of the khaen. Come on, I can’t be the only melodica player who tries to imitate the sound of the khaen a lot, can I?
– And as a super extra-unrealistic fantasy, some sort of system like what the Blues Box people are building – an easy way to pitch bend without having to have an extremely fine key pressure variation.

Of course, such a beast with all those features would probably either be so heavy as to be unplayable, or have to be built of ultra-light high-tech materials and thus the plaything of the 1%, but surely <i>some</i> of those features could be workable. Especially if they’re already building ones with <i>some</i> duplicate rows of buttons.