[2] Blues has incorporated spirituals, work songs, field hollers, shouts, chants, and rhymed simple narrative ballads from the African-American culture.

She was a free-born black woman from Pennsylvania who was working as a schoolteacher in South Carolina, instructing both slaves and freedmen, and wrote that she "came home with the blues" because she felt lonesome and pitied herself.

African-American singers voiced their "personal woes in a world of harsh reality: a lost love, the cruelty of police officers, oppression at the hands of white folk, [and] hard times".

The big kora of Senegal and Guinea are played in a rhythmic-melodic style that uses constantly changing rhythms, often providing a ground bass overlaid with complex treble patterns, while vocal supplies a third rhythmic layer.

[26] Reverend Gary Davis[27] and Blind Willie Johnson[28] are examples of artists often categorized as blues musicians for their music, although their lyrics clearly belong to spirituals.

Charles Peabody mentioned the appearance of blues music at Clarksdale, Mississippi, and Gate Thomas reported similar songs in southern Texas around 1901–1902.

In the 1930s, Lomax and his son Alan made a large number of non-commercial blues recordings that testify to the huge variety of proto-blues styles, such as field hollers and ring shouts.

[47] The first appearance of the blues is usually dated after the Emancipation Act of 1863,[38] between 1860s and 1890s,[2] a period that coincides with post-emancipation and later, the establishment of juke joints as places where African-Americans went to listen to music, dance, or gamble after a hard day's work.

[51] A form of this pre-blues was heard in slave ring shouts and field hollers, expanded into "simple solo songs laden with emotional content".

[52] Blues has evolved from the unaccompanied vocal music and oral traditions of slaves imported from West Africa and Black Americans in rural areas into a wide variety of styles and subgenres, with regional variations across the United States.

However, when rural black music began to be recorded in the 1920s, both categories of musicians used similar techniques: call-and-response patterns, blue notes, and slide guitars.

Blues performances were organized by the Theater Owners Booking Association in nightclubs such as the Cotton Club and juke joints such as the bars along Beale Street in Memphis.

Georgia also had an early slide tradition,[78] with Curley Weaver, Tampa Red, "Barbecue Bob" Hicks and James "Kokomo" Arnold as representatives of this style.

Performers such as Frank Stokes, Sleepy John Estes, Robert Wilkins, Kansas Joe McCoy, Casey Bill Weldon and Memphis Minnie used a variety of unusual instruments such as washboard, fiddle, kazoo or mandolin.

[83] Ma Rainey, the "Mother of Blues", and Bessie Smith each "[sang] around center tones, perhaps in order to project her voice more easily to the back of a room".

Smith would "sing a song in an unusual key, and her artistry in bending and stretching notes with her beautiful, powerful contralto to accommodate her own interpretation was unsurpassed".

[86] These blueswomen's contributions to the genre included "increased improvisation on melodic lines, unusual phrasing which altered the emphasis and impact of the lyrics, and vocal dramatics using shouts, groans, moans, and wails.

"[87] Urban male performers included popular black musicians of the era, such as Tampa Red, Big Bill Broonzy and Leroy Carr.

[88] Chicago boogie-woogie performers included Clarence "Pine Top" Smith and Earl Hines, who "linked the propulsive left-hand rhythms of the ragtime pianists with melodic figures similar to those of Armstrong's trumpet in the right hand".

[99] After Phillips discovered Elvis Presley in 1954, the Sun label turned to the rapidly expanding white audience and started recording mostly rock 'n' roll.

[104] In the late 1950s, a new blues style emerged on Chicago's West Side pioneered by Magic Sam, Buddy Guy and Otis Rush on Cobra Records.

King introduced a sophisticated style of guitar soloing based on fluid string bending and shimmering vibrato that influenced many later electric blues guitarists.

Major artists of the Texas style are Johnny Winter, Stevie Ray Vaughan, the Fabulous Thunderbirds (led by harmonica player and singer-songwriter Kim Wilson), and ZZ Top.

However, beginning in the 1990s, digital multi-track recording and other technological advances and new marketing strategies including video clip production increased costs, challenging the spontaneity and improvisation that are an important component of blues music.

The early African American rock musicians retained the sexual themes and innuendos of blues music: "Got a gal named Sue, knows just what to do" ("Tutti Frutti", Little Richard) or "See the girl with the red dress on, She can do the Birdland all night long" ("What'd I Say", Ray Charles).

The 12-bar blues structure can be found even in novelty pop songs, such as Bob Dylan's "Obviously Five Believers" and Esther and Abi Ofarim's "Cinderella Rockefella".

[citation needed] Almost 30 years later, Mahal wrote blues for, and performed a banjo composition, claw-hammer style, in the 2001 movie release Songcatcher, which focused on the story of the preservation of the roots music of Appalachia.

The film drew many of the biggest living influencers of the rhythm and blues genre together, such as Ray Charles, James Brown, Cab Calloway, Aretha Franklin, and John Lee Hooker.

King, Bo Diddley, Erykah Badu, Eric Clapton, Steve Winwood, Charlie Musselwhite, Blues Traveler, Jimmie Vaughan, and Jeff Baxter.

He asked several famous directors such as Clint Eastwood and Wim Wenders to participate in a series of documentary films for PBS called The Blues.