The lyrics in blues music are very important. They aren't just words to fill in a melody or mere entertainment. Blues lyrics are a reflection of the writer and performer's emotional state. This is a tradition that stems from the beginnings of blues, as many blues musicians were freed slaves or born into poverty and had to endure many hardships, including poor work conditions and racism. Blues lyrics often reflect frustration and sadness but can also reflect optimism and hope. Either way, blues lyrics are an emotional extension of the artist.
Instrumentation for blues music varies. The earliest blues music was nothing more than field hollers and chants from slaves in the Deep South, used to make it through the rough work days. These were of African origin and often revolved around a call-and-response format. The most basic blues instrumentation is the voice and a steel-string guitar. This is the instrumentation of what is known as the Delta blues. Blues musicians moved to Northern cities, such as Chicago and New York City, during the 20th century to find work and began expanding the instrumentation of blues and electrifying it. Electric blues bands use electric guitars and basses, drums, piano and other instruments.
Blues music has many structures, but the oldest and most enduring is the lyrical AAB structure. In AAB, the performer sings a lyric and, to drive the point home further, repeats it in a second A section. The B section resolves the lyrical theme with a new lyric, often commenting on the A sections. For example, in the Elmore James song "Dust My Broom," James sings "I'm gon get up in the mornin', I believe I'll dust my broom," the A section, twice and concludes the song with the B section lyric "I quit the best girl in lovin', now my friends can get my room."
The 12-bar blues is the most common form of blues music, although there are variations such as 8-bar and 16-bar blues. There are three four-bar segments in a 12-bar blues song that follows the AAB lyrical pattern. Three chords are involved, the I, IV and V chords. The first four-bar segment is usually dominated by the I chord, but the IV sometimes appears in its second bar. The next four-bar segment starts on the IV chord and often returns to the I chord in its third and fourth bars. The last four-bar segment is dominated by the V chord but sometimes goes to the IV chord before resolving on the I (or the V if the song repeats.)
According to blues legend Willie Dixon, "The blues are the roots; everything else is the fruits." Blues music is one of America's first original musical inventions, along with jazz. Because the blues developed and spread by word of mouth, it has no absolute boundaries. Its malleability has made it influential in many other forms of American music since its inception. Genres like rock 'n roll, soul, R&B, funk and hip-hop are all influenced by blues music.