Many people believe they are "tone deaf", but are they really? Can their condition be cured with training?
When Valerie was 11 years old she had an experience that deeply affected her. She was forced to stand up in front of the class and do a singing test while sick.
"I could barely manage to croak," she said. And then her music teacher announced to the whole class that she had the lowest mark.
"I felt devastated and humiliated. This was the start of my belief that I could not sing. I thought I was tone deaf."
For decades Valerie avoided singing in public, and even refused to sing in front of her husband, Peter.
Then one day, Peter convinced her to go along to the Tone Deaf Clinic. It changed her life — Valerie turned out to be a "dramatic soprano" and now sings with a choir she started herself called The Monday Nightingales.
"I never realised singing was something you could learn," said Valerie. "I thought it was something you were either able to do, or not."
And, apparently, this is what far too many people think.
Are you tone deaf?
Like Valerie, the vast majority of people who have labelled themselves as tone deaf actually are not, said psychologist Professor Bill Thompson from Macquarie University.
"Tone deafness is a lay term and is used very freely by many people just to mean they have difficulty singing," he said.
But it is likely with a bit of training they will learn to confidently hold a tune, he said.
Genuinely tone deaf people have a condition called congenital amusia, which makes it difficult for them to sing with the correct pitch.
These people cannot tell when they are out of tune, which can lead to some embarrassing situations.
"They would probably be the loudest in the choir, bellowing out and enjoying themselves and not realising they are completely off key," said Professor Thompson, who specialises in music cognition.
Congenital amusia is likely caused by a fault in the brain's ability to discriminate between small differences in pitch, but in some people the problem may actually be a disconnection between parts of the brain that pick up sound and parts of the brain that understand it.
Amusia is a problem with both producing and hearing pitches, since you generally have to hear to produce the right sound.
People who think they cannot sing do not necessarily have amusia, but may just need training in how to produce the right sound, or — less commonly — need a hearing defect attended to.
What you told us on Facebook about your singing
While officially, only 1.5 to 4 per cent of the population have congenital amusia, nearly 20 per cent of those we polled on Facebook last year classified themselves as "tone deaf". Here are some of comments that accompanied the poll:
"There are actually laws against my singing."
"Some days I'm a rock star, other days I'm a screeching cat. The one thing that doesn't stop me from singing no matter how I sound is that it makes me feel happy, instantly! And also helps me work through difficult emotions."
"I have it on good authority that it's not a pleasant sound. My own child asks me to stop singing."
"Every time I sing in the shower, the neighbours shut their windows."
Can you blame mum and dad?
Genes do play a role in our ability to sing in tune and definitely have a bearing on musical ability.
But because our brain is "plastic", there is also an important interaction between genes and environment that helps determine our ability to sing.
Being exposed to music in our early years and being encouraged by adults to sing is key, said retired music educator Gillian Bonham, who ran the Tone Deaf Clinic that changed Valerie's life.
"Little magpies learn to sing by imitating their parents. If you don't have a parent or a teacher that you can imitate as a baby — then you don't learn how to do it," she said.
Ms Bonham said bad childhood experiences like Valerie's were often to blame for many people thinking they were tone deaf.
When Jill Freeman was about eight, she was singing when her dad told her to be quiet.
"I stopped singing around the house and I didn't bother joining school choirs," she said. This set the stage for a life without music and the belief she could not sing.
That was until in 2009, when a notice in the paper asking readers whether they had ever been told they could not sing caught her eye.
It was an ad for the Tone Deaf Society at the University of Canberra, which was run by now-retired vocal educator and researcher Dr David Tattersall, who has investigated congential amusia and knows how few people really have it.
After a bit of training with Dr Tattersall, Jill graduated to his Choir of Limited Expectations, designed for those who had gained some confidence in singing. And these days, Jill sings with the University of Canberra Chorale, performing works like Judas Maccabeaus and Mozart's Requiem.
"I still don't consider myself very wonderful, but at least I can hold a part in a choir," she said. "We sing gorgeous music, we learn a lot, and it's great to be praised for a performance."
Some childhood experiences are far more extreme than Jill and Valerie's. One student at Ms Bonham's Tone Deaf Clinic was beaten as a child if she sang out of tune. In the end she was told to just mime along to avoid the cane.
Another student who had poor pitch told how she was made fun of by her parents and their friends.
"When her parents had dinner parties, they used to drag her out of bed to come down and sing to the guests so they could all laugh at her," said Ms Bonham.
"[Children's singing ability is] relegated to the dust bin at a very young age," she said. "This, I believe is cruel."
Learning to sing may not be as hard as you think
A handful of people, including American socialite and amateur soprano Florence Foster Jenkins and American Idol contestant William Hung, became famous for their out-of-tune singing.
But most people generally prefer to sing in tune, even if it is just so they can sing along with Happy Birthday or a Jingle Bells without fearing that people around will block their ears in horror.
If you feel you do not sing in tune, the chances are you just need some training and encouragement, said Professor Thompson.
While the Tone Deaf Clinic and Tone Deaf Society are no longer running, there is still help at hand.
"Get a singing teacher, join a community choir and you will probably improve," said Professor Thompson.
These kinds of environments can provide the support and rewards to motivate you to practice and strengthen the neural pathways necessary for good pitch, and to develop confidence in singing.
Of course, like any skill, there are a range of natural abilities and it will be harder for some to sing in tune than others. Improvement from training may not be as great as you would like, but it is important to keep things in perspective, said Professor Thompson.
"Most people don't sing very well," he said. But you may get good enough to make you feel like you hold your own in a choir, and that has its own benefits.
Synchronising with others leads to trust, he said. And singing in tune, and in time, in a choir offers a unique way of doing this.
Still think you're tone deaf?
The only way to tell if you are officially tone deaf is to be tested by experts.
But even if you are diagnosed, all may not be lost. Even people with amusia might be able to improve their pitch with training.
Tim Falconer is a Canadian journalist who was diagnosed with amusia and documented his efforts to improve his singing by intensive training.
It was not easy, and Tim said he would probably have given up trying to improve if he was not writing a book about amusia.
Listen to Tim before and after training and you can be the judge about how much he improved.
And hear more about tone deafness and singing on this week's
All in the Mind
and this Thursday's Life Matters.