Jonathan King, pictured on Top of The Pops in 1970, was a household name
To the current generation of teenagers the name Jonathan King means nothing.
But in the 1970s and early 1980s he was a singer and producer with a string of chart hits, a youth TV presenter and a household name.
Many in the music industry looked to him for guidance about what "the kids" were into both in the UK and abroad.
King, who had his first hit record in 1965 while still an student at Cambridge, claimed to have a hand on the pulse of Britain's youth.
His knowledge stemmed from a system of questionnaires which he handed out to teenagers, both boys and girls, wherever he found them.
King told the court he had probably compiled between 20,000 and 30,000 of these lists.
He would give the teenagers a list of subjects - family and friends, sport, music, cars, drugs, sex etc - and ask them to put them in order of priority.
David Jeremy, QC, prosecuting, said those boys who listed sex high in their list of priorities were then targeted by King.
The court was told that King's "method" was to befriend boys of 13, 14 and 15, and invite them to his home in Bayswater, west London.
But he was always assiduous in maintaining good relations with the teenagers' parents, who were often awe-struck at their sons' showbusiness connection.
On one occasion he dropped a boy off in a non-descript working class street in Luton, Bedfordshire, in his Rolls-Royce.
Another boy he gave a lift back to Shrewsbury, Shropshire and was given a meal by the youngster's grateful parents.
King would tell the boys - and their families - he was simply conducting "market research" into what young people were interested in.
Mr Jeremy said: "What he really gave them was his company, the company and interest of a celebrity.
"It is not hard to imagine how these young men would have felt flattered and excited by the attention of such a person.
"That is what this case, in a funny way, is about - not so much for sexual exploitation, but the exploitation of the young by the use of celebrity."
Former Radio 1 DJ Paul Gambaccini, who was a friend at the time, said he never knew about King's activities.
But he believes the industry may have turned a blind eye to his behaviour while he was still "bankable".
Mr Gambuccini said: "Most of the people in the record industry would not have cared.
"For the great majority, what they would have been interested in about Jonathan King was 'What can you do for me?'"
'Pop svengali'
The leader of the 1970s punk band Sham 69 says he watched King manipulate boys 30 years ago but had no idea of what he was really doing behind closed doors.
Jimmy Pursey said: "I'm absolutely shocked. What this man did and carried out in a disguise of this pop svengali. He's used all his intelligence and all of his ways of thinking to be so devious. It's unbelievable."
When King was arrested he described the allegations as "absurd" and continued to protest his innocence on his website.
With a characteristic lack of modesty, he compared himself to Oscar Wilde.
While in prison King wrote to a friend saying the boys he was involved with had consented.
But it was unclear whether he was referring to the five boys who made the allegations, or others.