The most widely known sub-genres of the blue are the Piedmont, Delta, Jump and the Chicago blues. It was during World War II that the blues went from the acoustic blues to the electric blues. During the 1960s and 1970s, a hybrid of the blues and rock formed called blues rock. Most blues songs will have a walking bass line or a shuffle playing under it. This gives the music a trance rhythm that allows the guitar player to improvise over it.
The lyrics are blues songs were originally derived from trouble with the African-American culture.
During the aftermath of World War II, the migration of African American’s into urban cities began. It was during this time that African-Americans began to receive livable incomes. This brought a new market to the music industry entirely, giving black musicians a voice in the industry. This marketing trend reinforced the importance of the urban blues clubs.
During the Civil Rights movement, many of the roots to African-American culture were brought back. This also gave way for the blues to take hold in the mainstream media. In the 1980s to now, the blues have gone through a lot of changes. Many of the songs today are more like rock and roll than blues.