Jazz guitarists are guitarists who play jazz using an approach to chords, melodies, and improvised solo lines which is called jazz guitar playing. The guitar has fulfilled the roles of accompanist (rhythm guitar) and soloist in small and large ensembles and also as an unaccompanied solo instrument.
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Until the 1930s, jazz bands used banjo because the banjo's metallic twang was easier to hear than the acoustic guitar when competing with trumpets, trombones, and drums. The banjo could be heard more easily, too, on wax cylinders in the early days of audio recording. The invention of the archtop increased the guitar's volume, and in the hands of Eddie Lang guitar became a solo instrument for the first time. Following the lead of Lang, musicians dropped their banjos for guitars, and by the 1930s the banjo hardly existed as a jazz instrument.
Amplification created possibilities for the guitar. Charlie Christian was the first to explore these possibilities. Although his career was brief, it was influential enough for critics to divide the history of jazz guitar into pre- and post-Christian eras.