From Mozart to Miles Davis, the harmonies of Western music rewire the brain, creating patterns of neural activity that strengthen with each new melody, a new study reported in The Houston Chronicle shows.

By monitoring the brains of people listening to classical scales and key progressions, scientists at Dartmouth College glimpsed the biology of popular song. The research shows how the musical mind hears the flat notes in Flatt and Scruggs, the sharps of the Harmonicats, and all five octaves in pop diva Mariah Carey's repertoire.

The flash-dance of these brain circuits, which process the harmonic relationship of musical notes, is shaped by a human craving for melody that drives people to spend more every year on music than on prescription drugs.

"Music is not necessary for human survival, yet something inside us craves it," said Dartmouth music psychologist Petr Janata, who led the international research team. "Our minds have internalized music."

Whatever the reason, the impact on the individual brain is measurable. Among expert musicians, certain areas of the cortex are up to 5 percent larger than in people with little or no musical training, recent research shows. In musicians who started their training in early childhood, the neural bridge that links the brain's hemispheres, called the corpus callosum, is up to 15 percent larger. A professional musician's auditory cortex—the part of the brain associated with hearing—contains 130 percent more gray matter than that of non-musicians.

The Dartmouth group scanned eight people with a functional magnetic resonance imager, or fMRI, as they listened to an eight-minute melody composed to move continuously through all 24 major and minor musical keys. The volunteers, who each had about 12 years of musical training, performed several music-related tasks while they listened in the scanner.

Although music activated many parts of the brain, the researchers discovered that everyone had just one area in common that tracked and processed melodies. That brain region, located near the center of the forehead, is called the rostromedial prefrontal cortex. This region, which links to short-term memory, long-term memory, and emotions, is different from areas involved in more basic sound processing.

Slaving over music scales is tedium incarnate for many children. But those who persevere may thank their lucky stars for it when they reach the other end of their lives, reports The Canadian Press.

That’s because music training, especially if it is commenced at a young age, may change the brain in ways that protect it against the ravages of time. That theory is being put forward by a team of Toronto-area researchers who will conduct a number of inter-related studies over the next few years to try to determine whether musical training protects the brain against dementia and other forms of cognitive decline in later life.

Lead investigator Christo Pantev puts it simply: “Music is magic.”

“There’s something about music that touches a chord in people. No pun intended,” agrees co-investigator Laurel Trainor, a professor of psychology at McMaster University in Hamilton, who was a professional pianist before joining the academic world. The third member of the research team is Larry Roberts, also a psychology professor at McMaster. Trainor’s colleagues are avid amateur musicians: Roberts plays piano and Pentev plays violin. Pantev is also is a neuroscientist at Toronto’s Baycrest Centre of Geriatric Care. He says he regularly sees elderly residents of the center who play music. There’s something different, something youthful, in their eyes, he insists.

“Anecdotally there are reports of conductors living very long lives,” Trainor adds. It has even been observed that people who take up music late in life—learning an instrument after they retire, for instance—seem to reap cognitive benefits, she notes.

The effect is often attributed to the “use it or lose it” ideal of brain function: if you don’t continue to tax your brain, it will stagnate and decline. But this research team believes there is something intrinsically different about learning to play the piano at age 72 than, say, learning to play bridge.

Mozart started listening to music before he was born, and by age four was already beginning to compose his own. Of course, not every child exposed to music in the womb will display such genius, but Reuters reports that Don Campbell—musician, teacher, and author of the 1997 best-seller "The Mozart Effect”—believes a little music early on can produce huge benefits.

And, he insists, Mozart does it better than anyone else. "The power of music has to do with patterns and the timing of perception," Campbell told Reuters in an interview. "What we are looking for from the music is form, repetition, variation, clarity and—overall—just not too much.

Campbell, an American who travels the world teaching about the beneficial qualities of music, has launched a series of "Mozart effect" CDs with compilations of pieces aimed at babies ranging from unborn fetuses through tantrum-throwing toddlers to demanding schoolchildren.

Campbell stresses he is not out to create child prodigies or encourage pushy parents. His stated aim is to convince parents, doctors, and teachers of music's role as a "powerful catalyst for healing, creativity and development."

"None of these CDs claims that if you listen to it you will get smart, or if you put this on, the child will instantly go to sleep. That's a bit naive," he explains. "What we are talking about here is developing sonic awareness. Everything that goes into the ear comes out as language. It becomes the tool of emotion and expression."

Scientists have discovered how we can hear a pin drop, the opening riff to “Pretty Woman,” or Saint-Saen’s Organ Symphony: a molecule that also enables us to feel cold and to savor pungent flavors such as mustard and cinnamon, reports the London Daily Telegraph. American research into how our ears work—down to the all-important molecule in the inner ear—could help in the development of new treatments for deafness.

When the eardrum vibrates, an equivalent sound is generated in the fluid within the inner ear. This structure, the snail-like cochlea, is tiled with cells that bristle with around 100 hairs arranged like organ pipes, tall ones at the back and short at the front.

Prof. David Corey, of Harvard Medical School, and colleagues describe in the journal Nature a set of experiments revealing the key molecule that generates an electrical signal when the hairs move back and forth. It is called TRPA1 and forms a "trap door" that is tugged open when a passing sound makes the hair bundle tilt, allowing charged atoms to flood into the hair cell.

This marks the beginning of an electrical signal that tells the brain about the pitch, volume and duration of a sound. Another member of the team, Dr Jeffrey Holt, of the University of Virginia, says: "This is one of the most significant findings in sensory biology, detailing an ingeniously simple but remarkably sensitive system."