QUESTION: How many backup singers have become bigger than the star they backed?
The four most famous are Elton John, Marvin Gaye, Whitney Houston and Mariah Carey.
Elton John provided piano and vocals for many acts when he started out in the music business.
In 1968, while still Reg Dwight, he provided vocals for Tom Jones' hit Delilah, and also lent his voice to The Scaffold's song Lily The Pink.
He continued to work as a session musician even as he released his first albums, perhaps most prominently playing piano on songs by The Hollies including He Ain't Heavy, He's My Brother.
Elton became the best-selling star of the 1970s and the fourth biggest of all time.
The four most famous are Elton John, Marvin Gaye, Whitney Houston and Mariah Carey. In the photo: the young Elton John
Whitney Houston (pictured) sang background vocals on songs by artists ranging from Chaka Khan to Lou Rawls and her mother, Cissy
Marvin Gaye, the greatest soul singer of his generation, started out singing background vocals for bands like The Marquees, The Moon Glows, Billy Stewart and Chuck Berry.
Gaye also provided drums on a number of Motown hits, including Martha and the Vandellas' Dancing In The Street (which he co-wrote) and The Marvelettes' Please Mr Postman.
Whitney Houston sang background vocals on songs by artists ranging from Chaka Khan to Lou Rawls and her mother, Cissy.
Whitney became one of the biggest pop stars of all time, selling more than 200 million records worldwide.
Mariah Carey worked as a backup singer for Brenda K. Starr and sang on her hit power ballad I Still Believe.
Starr helped Carey get her demo tape to Columbia Records and get her start in the industry.
Carey recorded I Still Believe in 1998 as a tribute to her mentor.
Keith Watson, Horsham, West Sussex
QUESTION: Does the Norwich system of undercrofts still exist?
Norwich's undercrofts are medieval vaulted cellars built beneath buildings, mainly in the 14th and 15th centuries, during the city's heyday as a center of trade and commerce.
The underground spaces were storage facilities for valuable goods such as textiles, wine and spices and provided a safe and climate-controlled environment.
They are unusual in being built mainly of brick, due to the shortage of stone in the area.
The underbuild often had elaborate vaults and was accessed by stairs from the main building above.
They were often found under the homes, shops and church buildings of wealthy merchants.
Today, around 70 still exist in Norwich, although many remain hidden under modern structures. This surviving substructure is a testament to the city's architectural ingenuity and economic prosperity during the Middle Ages.
Some of the most accessible examples can be explored beneath buildings such as the Strangers' Hall and St Andrew's Hall.
The one under the Guild Hall was probably a prison. Other examples can be found under Bridewell, the Assembly House, Dragon Hall and Curat House.
The undercrofts reflect Norwich's importance as a trading center in the medieval period.
LT Cowan, Dereham, Norfolk
QUESTION: Did the Nazis carry out deception operations similar to our Operation Mincemeat?
According to Sun Tzu, 'All warfare is based on deception' and Operation Mincemeat was a classic.
It involved planting a corpse with false documents to deceive the Germans about Allied invasion plans in the Mediterranean.
Its success depended on a deep understanding of how the Germans processed intelligence.
The Germans understood the value of deception. Operation Kreml was intended to mislead the Soviets about the true purpose of their summer 1942 offensive.
The Germans carried out a series of diplomatic and military feints, pretending to prepare for another invasion of Moscow, rather than the south of the Soviet Union.
England spiel ('England Game') or Operation North Pole was an operation by the German Abwehr (military intelligence service) in which the Germans captured Dutch resistance agents working for their British counterpart, the Special Operations Executive (SOE).
They used their radio transmitters to send misleading messages back to Britain.
The Germans tricked the SOE into thinking their agents were still operational, leading to the arrest or murder of even more agents who were parachuted into the Netherlands.
It was a complex operation that lasted almost two years (1942-1944). Operation Greif in 1944, conceived by Hitler himself, was led by Waffen-SS commando Otto Skorzeny.
The aim was to sow confusion among Allied forces during the Battle of the Bulge by using German soldiers disguised as American troops to capture one or more bridges over the Meuse before they could be destroyed. It failed.
John Hillman, Corbridge, Northumberland
