An inflammation referred to as 'guitar nipple' was mentioned in the British Medical Journal in 1974. It is caused by rubbing from the guitar soundbox.
Guitar-string dermatitis is another occupational hazard for guitarists.
In 1999 a Pennsylvania man tried to sue God for not granting him the skills to play the guitar.
Presidents Reagan and Bush, as God's earthly representatives, were named as co-defendants along with a number of religious leaders and other politicians.
The case was thrown out.
The smallest guitar in the world is made of silicon and its length is one-twentieth the thickness of a human hair.
It is strummed by a laser, played in a vacuum chamber at Cornell University, and emits a sound too high to hear.
The guitar's sixth string was added in the late 18th century.
A five-string guitar was known in the 16th century and a guitar with four double-strings existed in the 15th century.
The most expensive guitar ever sold was Jerry Garcia's "Tiger" guitar which fetched $850,000 (£583,992) at auction in New York in 2002.
A Versace guitar strap sold for £900 at auction in London in 1999.
The European Patent Office lists 2,388 guitar-related inventions.
Patents include an electronic calculator for guitar scales, patented by two Californians in 1999.
The guitarfish is shaped like a guitar.