More from So Expensive Editor's Note: In the video we say spruce is used for the bottom of the guitar, but Martin Guitars typically uses rosewood for bottoms. Martin acoustic guitars are some of ...

An acoustic guitar used by John Lennon in 1965 has set a Beatles instrument auction record A guitar used by John Lennon has become the most expensive Beatles instrument ever sold at auction.

Just like acoustic guitars, classical guitars have a wooden body with six strings. The strings, however, are slightly different: they're usually made of nylon or gut, unlike the metal strings used on ...