Professor Michael Casey stands at the front of the room ready to give the lecture. There is an energy behind the eyes - the look of a man who wants to let everyone in on a secret.

What he is about to tell this host of students and professors at Goldsmiths’ University, London, might, a few hundred years ago, have seen him accused of witchcraft. While most people dismiss psychics, astrology, and tarot card readers, as hokum, science has quietly gone ahead and achieved something directly from this realm - Michael Casey can read your mind...

As the Professor of Music and Computer Science at Dartmouth College (the renowned Ivy League research university based in New Hampshire, U.S.A.), his research has enabled him to play back the sounds from someone's mind by reading their brainwaves.

Astonishing as that sounds, it is just one of the achievements from the field of music psychology, which also includes breakthroughs in treating mental disease and pain-reduction.

By investigating such phenomena as the emotional effects of music, or our ability to recall songs not heard for decades, scientists have been able to further our understanding of how we process language, how we learn, and how the structure of the brain can change. In other words, music offers a framework by which researchers can understand how the brain works.

Perhaps this should not be surprising. After all, music is part of the fabric of our society. We chart historical events with it. It allows us to express ideas that we would have difficulty otherwise communicating. Some of us might even see in it the existence of God.

In this feature, we will see that, by investigating our relationship with music, these researchers are touching upon what it means to be human, what divides us from the rest of the animal kingdom. But as technology advances, are they crossing a line that will force us to redefine the very essence of that humanity?