As makers and players continued to investigate ways of increasing the volume of the electric guitar throughout the 1940s, it became clear that a solid body was a key design feature.

In a hollow guitar, the string's vibrations are transferred to the guitar's body. Since the pickup cannot tell string and body vibrations
apart, the signal can be jumbled.  In a solid-body guitar, the great mass of the solid body has minimal response to the vibrations of the strings. So the pickup "picks up" a cleaner signal of the strings' pure tone.

When the solid-body guitar is plugged into an amplifier, the electrical impulses created by the pickups are converted into sound by the amplifier. Special-effects boxes, such as the fuzz box that creates a distorted sound, can change the signal from the pickups, which changes the sound that the amplifier produces.