Guitars are typically classified as string instruments, having between four and 18 strings. They are generally divided into two categories: electric and acoustic. The string's vibration produces the tone for an acoustic guitar. The electric guitar, which was introduced in the 1930s, uses an amplifier and a loudspeaker to intensify the sound and affect the tone. Our colorful guitar-themed posters will add a touch of rock and roll style to any room in your house.