In the 1910s and 1920s Black singers, musicians, and songwriters had firmly established blues as a new popular song genre. The genre grew through sheet music, traveling shows, “race records,” and vaudeville, a form of theater that included musical, dance, and comedic acts. Blues had also become one of the foundational components of the era’s jazz music. It made inroads in mainstream popular song and in the repertoires of country music artists as well as in several ethnic genres such as Louisiana Cajun and Hawaiian music.

As the 1930s dawned, so did the Great Depression. The new decade’s blues themes often reflected the era’s hard times in titles such as “Unemployment Stomp,” “Working on the Project,” and “W. P. A. Blues.” Vaudeville acts were driven out of theaters by the new medium of talking pictures, and blues virtually disappeared from sheet music. Other than in a few remaining traveling shows like the Rabbit’s Foot Minstrels, live blues were mainly heard at small local venues. These included house parties, community picnics and fish fries, cafés, roadhouses, honky-tonks, juke joints, and urban saloons. Often the music was performed by a singer accompanied only with guitar or piano. Some performers busked for tips on street corners or in such public places as railroad depots, barbecue stands, parking lots, and store porches. There were no touring circuits besides those that singers could create for themselves. Most artists achieved only local or regional fame. The ones who traveled often did so by hoboing by rail and hitchhiking by automobile. Under these rough conditions blues became increasingly a male-dominated genre. Women found few venues where they could comfortably perform, although a few vaudeville blues divas of the 1920s, like Bessie Smith, Ma Rainey, and Ida Cox managed to extend their careers through appearances in traveling shows.

Blues were seldom heard on the radio and almost never in the movies. Both media remained oriented to the tastes of the white middle class. The record companies that had dealt with blues in the 1920s all went bankrupt or changed owners as sales plummeted in the early years of the Depression. By the mid-1930s, however, the industry rebounded. This was thanks to the proliferation of jukeboxes, budget pricing, marketing through chain stores, and an “assembly line” approach to recording. Some blues singer-guitarists from the South, such as Mississippi’s Robert Johnson and North Carolina’s Blind Boy Fuller, recorded up to a dozen songs in a session, as did St. Louis–based pianists like Roosevelt Sykes and Peetie Wheatstraw.

Chicago, with its Black population swollen from the Great Migration out of the rural South, became the main center of blues recording. Three record companies dominated the scene: Decca, RCA Victor with its Bluebird label, and American Record Corporation operating under the Vocalion, OKeh, and later the Columbia labels. They supplied a steady stream of blues by singers who could provide their own accompaniment and contribute original songs on novel themes. Impoverished recording artists were often persuaded to sell their songwriting rights to publishing companies for a few extra dollars instead of waiting for the uncertain promise of royalties. As economic conditions slowly improved in the last half of the decade, small blues combos such as the Harlem Hamfats and Big Bill and His Chicago Five began to appear on records mixing string instruments, piano, and horns. Some recording stars, such as Big Bill Broonzy, Memphis Minnie, and Tampa Red, also began to adopt the electric guitar.

By the beginning of the 1940s the Depression had eased, but America would soon be involved in World War II. The service of Black GIs in defense of a nation that still discriminated against them led to an intensification of the push for racial equality. This was reflected in the blues through a louder, more aggressive, sound and rhythm. Singers like Arthur “Big Boy” Crudup and Lightnin’ Hopkins recorded with electric guitar or in small combos, often with a drummer. Riff-based “boogie woogie” tunes by pianists like Albert Ammons and Jimmy Yancey and guitarists like John Lee Hooker also became popular. Big jazz bands were forced to scale down during the war. Small combos known as “jump bands” emerged featuring blues vocalists like Louis Jordan. Some of these groups were fronted by singers such as T-Bone Walker or B. B. King who played lead electric guitar in a jazzy style. Many blues vocalists, such as Roy Brown, Big Maybelle, and Wynonie Harris, adopted a “shouting” style of singing. Others, like Charles Brown and Cecil Gant, became sophisticated blues “crooners.” Both vocal styles conveyed Black assertiveness and advancement. Black “folk singers,” such as Lead Belly (Huddie Ledbetter), Josh White, and Big Bill Broonzy, included blues as part of their concert programs. They began to reach white and international audiences, as did some of the boogie-woogie pianists and jazzy combos. Occasionally, blues artists could be heard live on special radio broadcasts. Blues records were increasingly played on the radio by “disc jockeys.” A “chittlin’ circuit” network of clubs provided blues singers and their bands with touring opportunities. Toward the end of the decade small combos featuring amplified guitar and harmonica, piano, and drums would emerge in Chicago and other cities. These groups were led by artists such as Muddy Waters and Little Walter. Most of these developments were spearheaded and popularized by new independent record companies that emerged during and after World War II, as the more established companies lost touch with the new trends in Black music. They would lay the groundwork for the emergence of rock ’n’ roll in the following decade.