The Delta blues is one of the earliest styles of blues music. It originated in the Mississippi Delta, a region of the United States that stretches from Memphis, Tennessee in the north to Vicksburg, Mississippi in the south, the Mississippi River on the west to the Yazoo River on the east. The Mississippi Delta area is famous both for its fertile soil and its extreme poverty. Guitar and harmonica are the dominant instruments used. The vocal styles range from introspective and soulful to passionate and fiery.
Delta blues music was first recorded in the late 1920s. The early recordings consist mostly of one person singing and playing an instrument, though the use of a band was more common during live performances. The recording of early Delta blues (as well as other genres) owes much to Alan Lomax, who criss-crossed the Southern US recording music played and sung by ordinary people. His recordings number in the thousands, and now reside in the Smithsonian Institution.
Delta blues is a style as much as a geographical appellation: Skip James and Elmore James, who were not born in the Delta, were considered Delta blues musicians. Performers traveled throughout the Mississippi Delta, Arkansas, Louisiana, Texas, and Tennessee. Eventually, Delta blues spread out across the country, giving rise to a host of regional variations, including Chicago and Detroit blues.
Scholars disagree as to whether there is a substantial, musicological difference between blues that originated in this region and in other parts of the country. The defining characteristic of Delta blues is instrumentation and an emphasis on rhythm and "bottleneck" slide; the basic harmonic structure is not substantially different from that of blues performed elsewhere.
The Mississippi State Penitentiary at Parchman Farm was an important influence on several blues musicians who were imprisoned there, and was referenced in songs such as Bukka White's 'Parchman Farm Blues' and the folk song 'Midnight Special'. Thus Delta blues can refer to one of the first pop-music subcultures as well as to a performing style. This style of blues heavily influenced British Blues which led to the birth of early hard rock and heavy metal.
By some, the term "Delta Blues" itself is seen as an invented "authenticity" mainly constructed by white folk revivalists in post-war times. Their "perception of the music’s authentic contours is rural, male, non-commercial, and permeated by sorrow." By this, they erase a large part of a supposedly 'inauthentic' history of the blues, especially sexual song.
See also National Geographic article 'Traveling the Blues Highway' by Charles E. Cobb, Jr. .