"Blues" was already a term applied to the musical tradition. The field holler leads to the work song, which leads to the spiritual and the blues song.
1920s to 1930s
Blues gets recorded. Ma Rainey and Bessie Smith ("St. Louis Blues") are the first singers to be recorded. W.C. Handy pens songs, establishing himself as "Father of the Blues."
In the Delta, Charlie Patton is first "star" of blues, performing country blues. Son House influences the mythic Robert Johnson. In Texas, Blind Lemon Jefferson form. In New Orleans, piano blues emerge. In the West, more bands. John and Alan Lomax conduct field recordings of blues musicians in the South such as Leadbelly for the Library of Congress Archive of Folk Songs.
As blacks migrate to the north, themes of highways and trains appear in music. Alan Lomax records Muddy Waters. Artists start to gain ground: John Lee Hooker, Howlin' Wolf, Robert Nighthawk, Little Walter, Johnny Shines, Mississippi Fred McDowell, Elmore James, Sonny Boy Williamson, and others. "King Biscuit Time" radio show broadcasts blues out of Helena, Ark. Muddy Waters moves to Chicago and "plugs in"; T-Bone Walker plugs in down in Texas a little later - electric blues is born.
Sun Records in Memphis, Chess Records in Chicago, and others support blues. Producer-musician Willie Dixon writes songs for greats, including "Hoochie Coochie Man" for Muddy Waters. Elvis Presley - white boy sings blues, then rock emerges.
In the late '50s, blues artists play for enthusiastic audiences in Europe.
Blues/folk revival. Festivals, such as Newport Folk Festival, spur interest. "Roots" music is embraced by white, college-educated audience. Paul Butterfield and Big Bill Broonzy revive. Legends are rediscovered. Son House, Lightnin' Hopkins, Bukka White, Skip Jones. Mississippi Fred McDowell. B.B. King cuts his classic "Live at the Regal" album in 1964. Koko Taylor becomes "queen of the blues."
British rock groups pay homage, most notably the Rolling Stones (named after a Muddy Waters's song), with cover songs and requests to meet and perform with legends.
1970s to 1980s
Dry spell of '70s with disco, soul, rock. Alligator Records forms. "The Blues Brothers" movie, like it or not, gives blues a boost. B.B. King thrives. Stevie Ray Vaughan cooks with his guitar-driven blues rock, inspired by the likes of Albert King, Otis Rush.
Sony releases Robert Johnson's "Complete Recordings" and sells half a million copies. Reissues from Smithsonian to Alligator to Yazoo (as well as from Europe) pour out.
Eric Clapton soars with his blues and blues-inspired work. Bonnie Raitt tours with blues greats.
House of Blues Entertainment company opens several clubs and establishes foundation to give musicians regular venues and promote blues. Receives some criticism for commercial marketing approach and featuring non-blues.
John Lee Hooker does Pepsi commercial. Some refer to hip-hop as the new blues.
More blues festivals than ever, more touring blues acts than ever, more clubs booking blues.