What's a harmonica?

What is this crazy thing - really??

WHAT'S A HARMONICA? Basic layout of all harmonicas
Basic history
Why the harmonica?
Harmonicas in schools
Harmonica family: diatonic, chromatic, tremolo, chord, bass, etc. - sound files for each

Who invented the harmonica and around what year?

The ten-hole, 20 reed instrument that we in the US refer to as a "harmonica" was invented by a Bohemian instrument maker named Richter around 1826. It consisted of ten holes and twenty reeds, with separate blow and draw reed plates mounted on either side of a cedar comb. Richter's tuning, utilizing a diatonic scale, became the standard configuration of what Europeans referred to as the Mundharmonika or mouth organ.

Sources: 1. Hohner Harmonica (manufacturer)
2. Harmonicas, Harps, and Heavy Breathers (book) Kim

Killer distort files

How harmonica is normally perceived:

As a "folk"-sounding instrument. Example: a little bit of "Five Hundred Miles" F:\old98\cool\fivehundedit.wav

DO-RE SCALE
4blow, 4draw, 5blow, 5draw, 6blow, 6draw, 7draw, 7blow

7blow, 7draw, 6draw, 6blow, 5draw, 5blow, 4draw, 4blow

This is the standard "do re mi fa so la ti do" scale we're all taught to sing in school and follows an easy "blow, draw, move up to next hole" pattern until you get to hole #6, where you blow-draw then move up to the next hole and draw again before the blow - same thing on the way back down.

Do-re bent scale 1-4     
The diatonic harmonica is set up to play chords on the bottom four holes, which is really great for a lot of reasons, but it also means that there are some "missing" notes on those holes if you want to play a standard "do-re-mi" scale there. What is necessary is to bend those notes in to create the scale notes you need. If you know how to bend notes, then this is a good exercise, not just for bending, but also for your ear to make sure you are hitting your bends at the right pitch. On the C diatonic harmonica, Do-re bent scale 1-4 is played like this:

1 blow, 1 draw, 2 blow, 2draw (bent down one whole step), 2 draw,
C D E F G

3draw (bent down one whole step), 3 draw, 4 blow
A B C

I've included the letter names of the notes here in case you want to check your bends by playing the notes on a guitar or keyboard as you are bending to make sure your bends are on pitch.