The solid-body electrical guitar gets its volume from the magnetic pickup installed within its body. This pickup responds to the vibration of the strings, transforming the energy into electrical impulses that are sent to an amplifier over a shielded cable. The amplifier converts the electric signal into sound (amplifies it) and plays it. The tone and volume of the sound are also adjusted on the instrument or on the amplifier during this process. In other words, an electric guitar requires an amplifier before it can really be considered to be an instrument for playing music.