Conceived in the early 1930s, the electric guitar became a necessity as jazz musicians sought to amplify their sound to be heard over loud big bands. When guitarists in big bands only had acoustic guitars, all they could do was play chords; they could not play solos because the acoustic guitar is not a loud instrument. Once guitarists switched from acoustic guitar to semi-acoustic guitar and began using guitar amplifiers, it made the guitar much easier to hear, which enabled guitarists to play guitar solos. Jazz guitar had an important influence on jazz in the beginning of the twentieth century. Although the earliest guitars used in jazz were acoustic and acoustic guitars are still sometimes used in jazz, most jazz guitarists since the 1940s have performed on an electrically amplified guitar or electric guitar.