precursor of rock and roll. The 1940s saw the increased use of blaring horns (including saxophones), shouted lyrics and boogie-woogie beats in jazz-based music. During and immediately after World War II, with shortages of fuel and limitations on audiences and available personnel, large jazz bands were less economical and tended to be replaced by smaller combos, using guitars, bass and drums. In the same period, particularly on the West Coast and in the Midwest, the development of jump blues, with its guitar riffs, prominent beats and shouted lyrics, prefigured many later developments. In the documentary film Hail! Hail! Rock 'n' Roll, Keith Richards proposes that Chuck Berry developed his brand of rock and roll by transposing the familiar two-note lead line of jump blues piano directly to the electric guitar, creating what is instantly recognizable as rock guitar. This proposal by Richards neglects the black guitarists who did the same thing before Berry, such as Goree Carter, Gatemouth Brown, and the originator of the style, T-Bone Walker. Country boogie and Chicago electric blues supplied many of the elements that would be seen as characteristic of rock and roll. Inspired by electric blues, Chuck Berry introduced an aggressive guitar sound to rock and roll, and established the electric guitar as its centerpiece, adapting his rock band instrumentation from the basic blues band instrumentation of a lead guitar, second chord instrument, bass and drums. In 2017, Robert Christgau declared that "Chuck Berry did in fact invent rock 'n' roll", explaining that this artist "came the closest of any single figure to being the one who put all the essential pieces together". Rock and roll arrived at a time of considerable technological change, soon after the development of the electric guitar, amplifier and microphone, and the 45 rpm record. There were also changes in the record industry, with the rise of independent labels like Atlantic, Sun and Chess servicing niche audiences and a similar rise of radio stations that played their music. It was the realization that relatively affluent white teenagers were listening to this music that led to the development of what was to be defined as rock and roll as a distinct genre. Because the development of rock and roll was an evolutionary process, no single record can be identified as unambiguously "the first" rock and roll record. Contenders for the title of "first rock and roll record" include Sister Rosetta