David Lowe, an ex-teacher at a Catholic public school was found guilty of historic sexual assaults on young boys in his care, including a choir boy who sang at his wedding.
English and music teacher at Westminster Cathedral Choir School, was convicted on Monday of abusing six boys under the age of 14 during the 1970s and 1980s.
The 61-year-old was also found guilty of indecently assaulting four boys during his time at Ampleforth College in Yorkshire.
A jury at Southwark Crown Court took nine-and-a-half hours to reach a guilty verdict of Lowe on 15 counts of indecent assault against 10 boys during 1978 – 1984.
The court heard evidence of how Lowe indecently assaulted some of the young boys in Westminster as they lay sleeping in communal dormitories.
He also fondled other pupils during individual singing lessons, in his office or flat, or as he smacked them on their bare bottoms as corporal punishment.
Prosecutor Philip Bennetts QC said: "David Lowe had a small group of pupils that he was extra-friendly with.
"He would leave sweets in his locker and notes, [like], 'You're very special, you deserve this, enjoy'".
A former Ampleforth student described Lowe as having a "mad-scientist look" and experienced "painful" and "bizarre" abuse during music lessons.
During his evidence, the pupil said he was just 10 when he was indecently assaulted during private piano lessons in the early 1980s.
"The bit that I remember, because it was most disturbing, was that he was pressing really quite hard, to the extent it was quite painful, in my crotch area with his hand in a sort of cup-position," he told the court.
"It was painful, it was bizarre and it was inappropriate."
Another victim, who was a pupil at Westminster Cathedral Choir School, told police he was among "a select group of boys" who was picked to sing at Lowe's wedding in 1981.
He was later sexually assaulted in Lowe's car after visiting him in Yorkshire.
The judge told Lowe warned Lowe that he would "receive a sentence of imprisonment on the offences on which you now stand convicted."