Delta blues is probably the earliest form of the blues, emerging during the 1800s in the Mississippi delta region of the United States. The musical traditions of slaves brought to the American south from Africa blended into "field hollers" and work songs that grew into the blues, which during the 20th century led to musical genres as diverse as jazz, rock and roll, and rhythm and blues.

The Delta blues grew from music made by people with few instruments and limited resources. Bands were rare, and most musicians worked solo. Harmonica and guitar, especially slide guitar, are the most common instruments. With no formal training, the patterns in Delta blues are often uneven, and the lyrics are more spoken than sung.http://www.pbs.org/theblues/roadtrip/deltastyle.html

Blues artists were recorded commercially in the 1920s and 1930s, but their songs did not receive wide release or promotion. Instead, these "race records" were released and promoted only within the black community, and were considered to be of little interest to whites.

Beginning in the 1930s, folklorists John Lomas and his son Alan began traveling through the Mississippi delta region, searching out and recording the influential blues musicians in the area. In some cases, these recordings are all that exist of these musicians; in other others, the recordings led later musicians to search out the early blues pioneers.http://www.thebluestrail.com/artists/mus_jal.htm