A solid-body musical instrument is a string instrument such as a guitar, bass or violin built without its normal sound box and relying on an electromagnetic pickup system to directly detect the vibrations of the strings; these instruments are usually plugged into an instrument amplifier and loudspeaker to be heard. Solid-body instruments are preferred in situations where acoustic feedback may otherwise be a problem and are inherently both less expensive to build and more rugged than acoustic electric instruments.

An electric guitar is a guitar that requires external amplification in order to be heard at typical performance volumes, unlike a standard acoustic guitar. It uses one or more pickups to convert the vibration of its strings into electrical signals, which ultimately are reproduced as sound by loudspeakers. The sound is sometimes shaped or electronically altered to achieve different timbres or tonal qualities from that of an acoustic guitar via amplifier settings or knobs on the guitar. Often, this is done through the use of effects such as reverb, distortion and "overdrive"; the latter is considered to be a key element of electric blues guitar music and jazz, rock and heavy-metal guitar-playing. Designs also exist combining attributes of the electric and acoustic guitars: the semi-acoustic and acoustic-electric guitars.