Blues is the name given to both a musical form

Musical form

The term musical form refers to the overall structure or plan of a piece of music, and it describes the layout of a composition as divided into sections...

 and a music genre

Music genre

A music genre is a categorical and typological construct that identifies musical sounds as belonging to a particular category and type of music that can be distinguished from other types of music...

 that originated in African-American communities of primarily the "Deep South

Deep South

The Deep South is a descriptive category of the cultural and geographic subregions in the American South. Historically, it is differentiated from the "Upper South" as being the states which were most dependent on plantation type agriculture during the pre-Civil War period...

" of the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 at the end of the 19th century from spirituals

Spiritual (music)

Spirituals are religious songs which were created by enslaved African people in America.-Terminology and origin:...

, work song

Work song

A work song is a piece of music closely connected to a specific form of work, either sung while conducting a task or a song linked to a task or trade which might be a connected narrative, description, or protest song....

s, field holler

Field holler

Field Hollers as well as work songs were African American styles of music from before the American Civil War, this style of music is closely related to spirituals in the sense that it expressed religious feelings and included subtle hints about ways of escaping slavery, among other things...

s, shouts

Ring shout

A shout or ring shout is an ecstatic, transcendent religious ritual, first practiced by African slaves in the West Indies and the United States, in which worshipers move in a circle while shuffling and stomping their feet and clapping their hands...

 and chant

Chant

Chant is the rhythmic speaking or singing of words or sounds, often primarily on one or two pitches called reciting tones. Chants may range from a simple melody involving a limited set of notes to highly complex musical structures Chant (from French chanter) is the rhythmic speaking or singing...

s, and rhymed simple narrative ballads. The blues form, ubiquitous in jazz

Jazz

Jazz is a musical style that originated at the beginning of the 20th century in African American communities in the Southern United States. It was born out of a mix of African and European music traditions. From its early development until the present, jazz has incorporated music from 19th and 20th...

, rhythm and blues

Rhythm and blues

Rhythm and blues, often abbreviated to R&B, is a genre of popular African American music that originated in the 1940s. The term was originally used by record companies to describe recordings marketed predominantly to urban African Americans, at a time when "urbane, rocking, jazz based music with a...

, and rock and roll

Rock and roll

Rock and roll is a genre of popular music that originated and evolved in the United States during the late 1940s and early 1950s, primarily from a combination of African American blues, country, jazz, and gospel music...

 is characterized by specific chord progressions, of which the twelve-bar blues chord progression is the most common.