I spend a lot of my time designing user interfaces to be as usable, easy on the eye and generally as elegant as possible so I tend to notice other peoples idiocies and (very occasionally) other peoples genius.

The harmonica is an example of both (sort of). To get a major scale from hole 4 it goes:

blow, suck,

blow, suck,

blow, suck,

… suck, blow.

Doh! Let’s just make it complicated shall we? But it is actually a piece of genius. Why everyone thinks they can play the harmonica is because where ever you blow not only is every note in the same scale EVERY 3 adjacent holes form a major triad of that scale (the root chord). Brilliant, every note fits in with the scale and if you (deliberately or accidentally) get more than one hole it harmonizes with itself! How can you go wrong?

Well obviously getting the right notes to any particular tune still requires a bit of skill - the clever thing is the wrong notes still sound OK(ish).

And then it all goes wrong. People are just perverse. The harmonica contains all the notes that you need of the major scale which accounts for most “traditional” western music. The blues scale is different, you need different notes so blues and rock players play “cross harp” - they take a C harmonica, bend a load of the notes (by sucking “wrong”) and play in a G blues scale. Even if you gave them a harmonica with the right notes for the blues scale it wouldn’t work because the bending is what gives that beautiful distorted sound and allows you to play a bit “off key” for bluesy dissonance and tension.

So great design but Qu’est-ce que c’est le point?

NB This all refers to a 10 hole diatonic harmonica - they do make all sorts but this is the common one!