Boys tend not to join choirs because they think their singing voices "do not sound like boys", research suggests.
Some boys develop a real love of choir singing
Dr Martin Ashley of the University of the West of England says they associate "boy" bands with adult voices.
He found pupils in a range of schools thought bands and even soloists "cool" - but regarded choristers as "weird".
At least the majority did - but he estimates that about one in 20 boys would love to be in a choir, and would develop a real love of singing.
In schools, boys are highly unlikely to join the choir - even though many of them will sing their hearts out at football matches on a Saturday.
The researchers' starting point was that it has long been known that singing is not top of boys' wish lists, a reason commonly given being that boys do not want to "sound like girls".
But that was not the reason. What they found was a vocal redefinition of the word "boy".
Dr Ashley worked with a nationally representative sample of schools of different sorts and five cathedral choirs.
The schools included rural and urban performing arts colleges, inner-city and Welsh-speaking comprehensives, a boys' grammar school, three cathedral choir schools and a similar range of primary schools.
He says he also interviewed, in depth, eight young male performers, some well-known, but promised them anonymity.
"The first thing we discovered is that it's choral singing that's in trouble," he said.
"Solo or band singing is actually quite 'cool' for boys.
"Not all boys will go on stage, but a surprising number sing along in private with their iPods."
But they are scared of being heard by others, especially girls their own age.
When Ernest Lough sold a million copies of Hear My Prayer in 1927, "boys" were aged between 10 and 15, wore short trousers and sang in high voices.
"Now, Robbie Williams is a 'boy' and he's 33. When young people listen to 'boys' singing, they hear the low voices of boy bands - and that's what they think boys are," Dr Ashley said.
"Imagine a young male, aged anything between nine and 14. He's not going to be able to make that sound.
"He's not going to be able to 'sound like a boy'."
So he will not live up to the role model - and girls will laugh at him.
"In secondary schools, we probably have to accept that for the time being.
"The real tragedy is in primary schools where the research has revealed that the sound of a boy soprano voice is so unfamiliar that most primary school children, when confronted with it, react with shock and disbelief.
"I've looked at what happens when cathedral choristers go in and sing to the children: they say it's weird and unnatural."
But secretly there are some boys who would love to do it, he says.
"Get him into a cathedral choir, and singing will become the love of his life."