Electronic music is created using electronic musical instruments, such as synthesizers, drum machines, and samplers. These instruments produce sound electronically, rather than through the vibration of strings, membranes, or air columns. A semi-acoustic instrument is an instrument that produces sound both acoustically and electronically. In other words, it uses a traditional sound-producing mechanism like strings, membranes, or air columns, and also uses electronics to modify or amplify the sound. An example of a semi-acoustic instrument is an electric guitar, which uses a traditional guitar body and strings, but also has an electronic pickup that converts the vibrations of the strings into an electrical signal that can be amplified.