Blues music was known to break down the stereotypes of Black people and play a role in the fight for justice and equality during the Jim Crow and racial segregation period of time. Historically, blues music was sung solo by a male artist that play instruments like the piano or the guitar. In the instance that it was sung by a woman, she was usually accompanied by a male pianist or guitarist. Most blues singers at this time were born and raised in the Deep South. Most blues music uses the twelve-bar AAB form or something similar to it.
Blues music places emphasis on individual expression and improvisation. The basic melodic structures of blues music originated from the field holler (or field cry) from folk music. Blues songs express feelings. The lyrics are realistic and serious, but may include exaggerations in the form of amplifications of the truth, and humor in the form of cleverness and irony. The songs include a large range of human emotions such as confidence and sadness. The songs are usually about love and sex.
Blues music includes a combination of European and African elements of music. Its form of voice harmonies and I-IV-V harmony in accompaniment, instrumentation, and strophic form come from European traditions. Its overall flexibility regarding style, rhythm, tone, and timbre come from Africa.
Along with blue notes and the blues scale, instruments are necessary in the construction and performance of blues music; they are known as the second voice. The electric guitar became a large part of blues instrumentation in the 1940s and 50s.
The boogie-woogie piano style formed in the 1930s and 40s due to self-taught pianists. This style includes repetitive riffs and improvised and syncopated melodies. In the 1940s and 50s, blues music gradually became more rhythmic and louder. This style was known as jump blues. In the 1970s, a melismatic, gospel-influenced style of blues emerged: soul blues.