Global sales of pre-recorded music total more than $40 billion.

It was at a concert in Minneapolis in 1954 that Al Dvorin first closed Elvis’s concerts with: “Ladies and Gentleman, Elvis has left the building. Thank you and good night.”

The first pop video was Bohemian Rhapsody by Queen, released in 1975.

In 1972 Leslie Harvey of Stone the Crows died after being electrocuted onstage in England. In 1976 Keith Relf, who used to play for The Yardbirds, was electrocuted by his guitar while playing in his basement. During a mid-performance in 1994 Ramon Barrero, a Mexican musician famous for playing the world’s smallest harmonica, inhaled the harmonica and choked to death.

Bob Dylan’s first professional performance was as opening act for John Lee Hooker at Gerde’s Folk City in New York, 1961.

When William McKinley’s wife Ida McKinley became first lady of the White House, she hated the color yellow so much that she made it a White House yellow-free zone. She even ordered the gardeners to yank every yellow flower out of the garden grounds.

Rutherford Birchard Hayes won lots of spelling contests when he was in elementary school.

Theodore Roosevelt found his favorite dog, Skip, wandering around the Grand Canyon. While Roosevelt had many dogs, Skip was the only one permitted to sleep in the presidential bed.

Millard Fillmore’s wife, Abigail Powers, was his former teacher and was the first First Lady to have a job after marriage.

President Grover Cleveland used his veto powers 584 times during his two terms in office. This is the highest record for any resident that served for two terms. For all the presidents, this is the second highest. First highest came from Franklin Delano Roosevelt, who died on his fourth term.

Milk chocolate was invented by Daniel Peter, who sold the concept to his neighbour Henri Nestlé.

Botanically speaking, the banana is a herb and the tomato is a fruit.

In 1994, Chicago artist Dwight Kalb sent David Letterman a statue of Madonna, made of 180lb of ham.

Americans eat twice as much meat as Europeans, gobbling up some 50kg (110 lb) per capita.

Plastic bottles were first used for soft drinks in 1970.

The coloured part of the eye is called the iris. Behind the iris is the soft, rubbery lens which focuses the light on to a layer, called the retina, in the back of the eye. The retina contains about 125 million rods and 7 million cones. The rods pick up shades of grey and help us see in dim light. The cones work best in bright light to pick up colours.

Your mouth produces 1 litre (1.8 pints) of saliva a day.

Over the last 150 years the average height of people in industrialised nations increased by 10 cm (4 in).

In the Middle Ages the length from the tip of the middle finger to the elbow was called an ell.

Fingernails grow nearly 4 times faster than toenails.

In 1894, Lord Kelvin predicted that radio had no future; he also predicted that heavier-than-air flying machines were impossible.

The paperclip was invented by Norwegian Johann Vaaler.

Traffic lights were used before the advent of the motorcar.

One hour before Alexander Graham Bell registered his patent for the telephone in 1876, Elisha Gray patented his design. After years of litigation, the patent went to Bell.

Count Alessandro Volta invented the first battery in the 18th century.