Along with its cousins, the accordion and the concertina, the harmonica got its start around 1820 in the German-speaking parts of Europe. Right from the beginning, harmonicas were called mouth harps (or mundharfe in German). No one knows for certain who invented the harmonica.
Early harmonica history in the United States
At first, harmonicas were made by hand by part-time workers in semirural areas of Germany. The Hohner company, which later grew to dominate the world harmonica market, made only 650 instruments in 1857, its first year of production.
By the mid-1870s, mechanization allowed Hohner alone to produce more than 50,000 instruments yearly. By 1900, Hohner was pumping out more than 3 million harmonicas a year, with most going to the United States. Meanwhile, mail-order catalogs helped distribute harmonicas to even the loneliest outposts.
By the mid-1880s, Midwestern music publishers were producing harmonica instruction books, attesting to the harmonica’s growing popularity. The books made no mention of such blues techniques as bending notes or playing the harmonica in a key different from its labeled key.
Prewar rural blues harmonica
During the 1920s, several harmonica players made records that give a picture of the earliest blues harmonica styles. Those recordings reveal some interesting facts:
During the 50 or so years since harmonicas had become widely available around 1870, southern rural players, both black and white, had evolved highly sophisticated abilities on the harmonica and developed styles that, though individual, shared many characteristics of technique, style, and repertoire.
Rural harmonica players often recorded without accompaniment while playing imitations of trains and fox chases, sonic depictions of hunting expeditions with driving, rhythmic chords that propel the chase, punctuated by vocal cries that imitate the hunters’ calls and yelping dogs.
Both black and white players played bent notes as a matter of course and used first and second positions about equally, but a few players also explored fourth, fifth, sometimes sixth, and even twelfth positions.
Traveling life and the migration north
In the South, black musicians gravitated to towns that offered relaxed racial attitudes, nightclubs for gigging, and radio exposure. The next step for the itinerant performer was one of the larger southern population centers, especially the so-called wide open towns where illegal Prohibition-era whiskey and Depression-era money both flowed freely under corrupt civic governments.
The biggest population magnets, though, were the northern and western cities that offered steady industrial jobs at wages much higher than could be found doing seasonal farm labor in the South. Later on, during the 1940s, the wartime shipbuilding industries in Los Angeles and the San Francisco area attracted a large influx of southern black folks, leading eventually to the West Coast blues styles.
Memphis and early urban blues
Urban recording artists mixed ragtime, early jazz, and hokum blues, derived from the stereotypes of old-time medicine shows. Hokum featured humorous and often saucy lyrics with thinly veiled sexual references.
In Memphis, Beale Street was the center of musical activity, and blues musicians there developed a ragtime-influenced style called jug band, named for the large whiskey jugs that players blew into to create trombone-like bass lines. Banjo, guitar, harmonica, and hokum lyrics with a jaunty air were typical of jug band music.
The prewar Chicago style
Before about 1947, two very different approaches to blues were heard:
Sophisticated, jazz-influenced blues using saxophones, trumpets, and other urban instruments reflected Chicago’s role as a magnet for jazz musicians beginning in the early 1920s.
At the same time, rural southerners brought country blues with them, but when transplanted to the city, it began to change. Guitars, harmonicas, and mandolins might still be the featured instruments, but lyrics began to reflect such urban concerns as bill collectors and the indignities of collecting welfare. The feel of the music changed, too, with the relaxed, stately country blues speeding up and becoming more rhythmically active.
The rise of amplified blues harmonica
Beginning sometime in the late 1940s, harmonica players started using amplification in a new way. With a small, portable amplifier and a cheap microphone, they would cup the mic in their hands, together with the harmonica, to create a highly concentrated sound that was loud enough to project over the din on street corners and in small nightclubs.
By the start of the 1950s, electric guitars and amplified harmonicas were the rule in Chicago blues bands, backed by drums, bass, and piano.
The postwar Chicago style
Early postwar attempts at recording transplanted rural artists reveal an uncomfortable grafting of country blues onto an urbane, jazz-influenced backing that doesn’t serve the direct, earthy character of the featured artists.
Here are some hallmarks of this style:
Electrified rhythm and lead guitar, including delta-style slide guitar, begins to buoy up the rhythm, while bass lines borrowed from boogie-woogie piano but played on the bass strings of the guitar start to give the music its own up-tempo character.
Amplified harmonica starts to take on a new role, as Little Walter adapts jazz and rhythm-and-blues saxophone stylings to blues harmonica and integrates swing seamlessly into down-home blues.
Simple, to-the-point drumming propels the beat more aggressively than either jazz or older rural blues.
Down-home piano that could be at home in a gospel setting embellishes the overall sound while staying within the flavor of blues harmony.
Regional harmonica styles
Small, independent record companies have long been important vehicles for blues artists to get their music to consumers. Some of the better-known regional companies highlighted blues harmonica and promoted early rock-and-roll. This combination later influenced the adoption of the harmonica by rock artists in the 1960s, who heard blues harmonica alongside the latest hits.
Rock, blues, and the 1960s
By the late 1950s, white teenagers were obsessed with rock-and-roll, while black audiences had largely moved on from the blues. The folk music movement of the 1950s presented Americans with an alternative to current popular music. Folk fans began to see blues musicians as a part of the folk movement, with several effects:
College students hired blues artists and bands to play concerts and dances on their campuses, and a whole circuit of campus touring began.
Young Caucasian males started taking up blues harmonica.
European and British music fans, who had been fascinated for several years with American music, especially jazz and blues, began promoting blues concerts in the UK and on the European continent.
Young British musicians started emulating the blues records they heard, resulting in British rock bands with notables on the mouth harp.
Modern blues
Musicians worldwide have been bitten by the blues harp bug, and the virus often mutates and starts to interact with its new host. Artists and the stylistic crossbreeding they’ve been working between blues and other styles include jump and swing's Dennis Gruenling, beatboxing's Son of Dave, and soul's Bobby Rush.