The electric guitar was invented by Adolf Rickenbacker in the 1930’s. Rickenbacker guitars are now commonly used in Rock and Pop music. The Rickenbacker 12 string was made famous by George Harrison of the Beatles. It is also used by Roger McGuinn of the Byrds and by Tom Petty. 12 string guitars contain six courses of two strings side by side, with the two strings tuned an octave apart. The 12 string has a singing quality and is great for both chords and picking melodies.
The classical guitar has nylon strings and is played with the fingers of the right hand rather than a pick. As the name suggests, this is the type of guitar used for classical music, but it is also commonly used for Flamenco, Folk, and World music. Some of the most famous classical guitarists are Andres Segovia, John Williams and Alirio Diaz. American fingerpicker Chet Atkins used an electric classical guitar.