An electric guitar is a type of guitar that uses pickups to convert the vibration of its steel-cored strings into electrical current, which is then amplified. The signal that comes from the guitar is sometimes electronically altered to achieve various tonal effects prior to being fed into an amplifier, which produces the final sound. The electric guitar was first used in jazz and has also long been used in many other popular styles of music, including almost all genres of rock and roll, country music, blues, ambient (or "new-age"), and even contemporary classical music.