Author: BBC World Service

What sounds heavenly to one person might sound like boring noise to another - but why are our musical preferences so different? Is it all down to what we hear growing up, or are other factors at play?

CrowdScience listener and music lover Jocelyne from Canada wants to know why she has a different song for every mood, and why she likes different music from her friends and family. Meanwhile in Italy, composer Elisabetta Brusa asks us whether the rules of harmony align with the laws of science, and should therefore not be broken.

We talk to both musicians and neuroscientists to explore the truth about harmony and discord. We find out how age, personality and experience all affect whether we find certain songs pleasing or offensive, and learn why the search for the true universals of music pleasure is a race against time.

Presenter: Marnie Chesterton Producer: Cathy Edwards

(Image: A couple laying in the grass listening to music on headphones. Credit: Getty Images)

Hypnosis has a long and controversial history, with its roots in animal magnetism or mesmerism, the theory developed by 18th Century German doctor Franz Mesmer. He believed he had discovered an invisible natural force possessed by all living things, and that he could channel this force for healing purposes.

Popularity of hypnosis has since waxed and waned, but was largely denounced as quackery until the 20th Century, when it began to be studied scientifically. However it is only in the last twenty years or so that is has become incorporated into mainstream science and medicine.

But is it a real phenomenon, asks listener Gratian from Poland; and Anton from Ireland wants to know how it works and what happens to people’s brains and bodies under hypnosis?

CrowdScience speaks to Dr Quinton Deeley, consultant psychiatrist and senior lecturer at the Institute of Psychiatry, who has used it in practice for many years, and Dr Amir Raz, a magician-turned-neuroscientist who is shedding light on how hypnosis works. To see how hypnosis is being used clinically, CrowdScience visits the Berkeley Clinic in Glasgow, Scotland, to witness a hypnotised patient having a tooth extracted with very little anaesthesia.

Meanwhile, presenter and self-confessed arachnophobe Nastaran Tavakoli-Far takes part in the Friendly Spider programme at London Zoo, an afternoon event that uses hypnotherapy and group therapy to ease or eliminate the fear of spiders.

Presenter: Nastaran Tavakoli-Far Producer: Helena Selby

(Image: A silver pocket watch swinging on a chain on a black background to hypnotize. Credit: Getty Images)

Electric cars are labelled as ‘zero emissions’ vehicles – but what does that really mean? Jack Stewart puts your questions about EVs to the experts. According to a new report by the Union of Concerned Scientists, just how green your EV is compared to a petrol or diesel vehicle, depends on how the electricity powering the battery was produced, as well as how cleanly the battery itself was manufactured. Jack also explores what could be a compelling alternative to plugging in – filing up with Hydrogen, and creating nothing but water as exhaust.

Presenter: Jack Stewart Producer: Rami Tzabar

(Image: Electric cars on charge. Credit: Getty Images)

For some it's a way to get closer to God, for others a tried and tested way to lose weight - but listener Amine wants to know if fasting has any other, unexpected health benefits? So presenter Marnie Chesterton cuts down on cookies and investigates the science behind low-calorie or time-restricted eating. She hears how some cells regenerate when we're deprived of food, which one researcher says could reduce breast cancer rates. And she finds out what happens in our brains when our bodies rely on our own fat reserves for fuel. Presenter: Marnie Chesterton Producer: Marijke Peters

(Image: Clock on an empty plate. Credit: Getty Images)

Why is it that computers are so much faster than brains at some tasks?

Or could human brains one day be used to better effect? Listener Praveen from India was wondering how it can be that supercomputers are so very powerful compared to the human minds that created them. So CrowdScience, with the help of a small voice-activated guest presenter, is off to discover how the first computers remembered what they were told, how a million processors are being connected together to mimic a small percentage of a human brain, and how the mind-boggling speeds of modern computing is enabling the current leaps in artificial intelligence.

Producer: Alex Mansfield Presenter: Marnie Chesterton

Speakers: Sarah Baines, David Lewis - Museum of Science and Industry, Manchester James Sumner, Steve Furber - University of Manchester Aldo Faisal - Imperial College, London.

(Photo: 3D transparent human head and brain image. Credit: Getty images)

Kenyan listener Docktor can’t help himself. When music is playing he must move to the beat and he wants to know why. What role does dance play in human evolution? And what does dance mean to us? To help answer the many twists and turns in Docktor’s questions, the CrowdScience team heads to one of the most vibrant and diverse dance scenes in the World, Havana in Cuba. For Cubans dancing is at the heart of their cultural identity. They tell stories, bond with others, practice religion and celebrate their African ancestry through dance ¬– which came to Cuba with the slave trade.

For all humans, dancing is intimately connected to our love of music and is likely to be one of our oldest cultural practices. But why would our ancestors have wasted energy on what superficially seems to serve no survival benefits? Evolutionary anthropologist Bronwyn Tarr tells us that one clue lies in the brain. When we dance with others our brains reward us with a cocktail of feel-good hormones and this likely leads to profound social effects.

Presenter Anand Jagatia gets challenged on the dance floor, discovers how deeply rooted dance is in Cuban society and why we should dance more.

Presenter: Anand Jagatia Producer: Louisa Field

(Image: Dancers in Cuba)