Emerging from the Mississippi Delta region during the early 1900s, rural musicians like Son House and Robert Johnson cut their teeth on the South's house party and "juke joint" circuit. These performers crafted a style around simple, insistent refrains played on acoustic guitars. Known as country blues, this trend also coincided with the switch from gut to steel strings--enabling guitars to be heard beyond the confines of family parlors.
The commercial recording industry's birth during the 1920s allowed blues artists to be heard nationally for the first time. Inevitably, a new style arose. Labeling their rural peers as "primitives" who lacked professionalism, artists like Lonnie Johnson retained the driving beat, while emphasizing more intricate rhythmic patterns, according to the Arc Music website. This trend increasingly found voice on electric guitars, which mail-order catalogs made easier to buy.
By the 1930s, small groups effectively replaced the traveling solo performer as the dominant method of expression. Devastated by the Great Depression, rural musicians began migrating northward to cities like Chicago. Small groups remained in demand while bandleaders like Louis Jordan tried a different approach, according to Arc Music. The beat became more frantic, but stringed instruments took a backseat to horn sections and a led vocalist. This style became known as "jump blues."
Blues became an increasingly urban phenomenon after World War II. Rebelling against what they saw as the jump style's melodic constraints, up-and-comers like Muddy Waters pioneered a rawer, back-to-basics approach--typically called "Chicago blues" or "deep blues." Chicago's Chess Records became a key player in documenting artists like Waters, along with the Indianola and Kent labels, which gave guitarist B.B. King--another notable Chicago-style exponent--his first exposure.
Following the 1950s rock 'n' roll explosion, blues artists weathered a lengthy era of obscurity. This trend reversed itself during the early 1960s, when white British teenagers melded their heroes' music with the louder, brasher and harder-edged sounds of the Rolling Stones and the Yardbirds. Guitarists like Peter Green of Fleetwood Mac became the new musical heroes, while bandleaders like John Mayall exerted a more influential role behind the scenes.
Two major trends have predominated since the 1960s-era blues boom tailed off. Labels like Chicago's Alligator Records and its Mississippi-based rival, Rooster, have dedicated themselves to documenting the electric blues style. Interest also remains high in rhythm 'n' blues- and soul-based music. A notable example came in 1996, when Arkansan Johnny Taylor's "Good Love" made the U.S. Top Ten in 1996, according to the PBS website.