World famous concert pianist John Briggs sexually abused five boys over a 25-year period, a jury at Bradford Crown Court was told.
He denies nine allegations of indecent assault on a male person and one of indecency with a child.
Prosecutor Nick Worsley told the jury Briggs’ alleged victims were then aged between ten and 16.
The oldest allegation dated back almost 45 years to 1969 when Briggs was in his early 20s and living with his mother in Crossflatts.
His alleged victim, now in his 50s, told the police Briggs put his hand down his trousers during piano lessons when he was aged ten to 12.
The man said the abuse began within weeks of him starting to take lessons with Briggs and took place at the piano on a shared stool and on the sofa afterwards at “debriefing” sessions following the weekly half-hour tuition.
He alleged Briggs, at that time a family friend, touched him inappropriately at every lesson.
He said he was very confused at the time and knew it should not be happening but it was his parents’ wish that he took the lessons.
The man said he did not tell anyone then but decades later, his mother asked if Briggs had “molested” him and he replied: “Yes”.
Mr Worsley told the six men and six women on the jury that Briggs’s second alleged victim was a 14 or 15-year-old piano student of his in the late 1970s.
He said Briggs, then living in Bingley, sexually abused him while making him do floor exercises to strengthen his stomach muscles for piano playing.
“He was very proud to be taught by Mr Briggs. He was put in for his Grade 8 exam, which was advanced for his age. He was fearful that if he said anything, that would be the end of his hopes as a pianist,” Mr Worsley said.
One day, the boy arrived at Briggs’ home for a “masterclass”, having been told he could play Briggs’ personal piano, the jury heard.
Briggs was wearing a pink dressing gown and told the boy to lie on a bed next to him.
Mr Worsley said Briggs was naked under the gown and took the boy’s arm, moving it towards his lower stomach area.
The court heard the boy ran from the house and spoke to his mother but nothing was done.
Mr Worsley said Briggs later rang the boy’s parents saying “their son had no talent and would never amount to anything as a musician”.
The next three complainants were members of Keighley Sea Cadets. Briggs’s mother had been president of the organisation and when she stepped down, her son replaced her.
The group was based in a building at Crossroads, Keighley, before moving to Briggs-Maritime House on the town’s Waddington Street, a building named after Briggs’s mother.
The alleged victim said Briggs massaged his crotch and photographed him modelling different outfits with his genitals exposed.
The man says Briggs paid him £80 to perform an indecent act on camera before the pianist crawled over the floor to indecently assault him.
Briggs is accused of indecently assaulting a cadet aged 14 in the early 1990s. He is said to have filmed him with a camcorder while he stripped off for a modelling session at his home.
A third cadet is alleged to have been groped by Briggs when he was 15.
He alleges the concert pianist told him: “Don’t worry, you’re with Uncle John.”
When interviewed by the police, Briggs denied any sexual assaults.
He said all the allegations were made up and it was “a vicious conspiracy against him”.
Cross-examined by Briggs’s barrister, Nick Askins, the trial’s first witness said he told his sister about 20 years ago that the concert pianist had “messed around” with him as a boy.
The man, giving evidence in court behind screens, could not recall ever asking Briggs to leave him alone when he allegedly molested him or refusing to go for his piano lessons.
He told the jury that some time after he had stopped having lessons, he went round to Briggs’s home in Bingley after he had been drinking and had sex with him.
He said he did not tell the police about this because he was ashamed.
The man alleged he had “full sex” with Briggs several times when he was aged 15, 16 or 17.
“I am ashamed of it. I am not proud of it. It is difficult,” he told the court.
He said he came forward last year to accuse Briggs of sexual assault after reading on the Telegraph & Argus website that the pianist had been charged with sexually abusing young boys.
Asked why he did not go to the police sooner, he replied: “I just did not feel as though I could.”
The trial, expected to last into next month, continues.