THE instant Derek Paravicini heard the sound of the music, he broke free from his parents' grasp and headed towards it. The little girl on the piano stool took a tumble as the then four-year-old boy, blind, autistic and severely learning impaired, pushed her out of the way and began playing in her place.

"It was utterly extraordinary," says Adam Ockleford. "He was hitting the notes with his hands, his feet, his nose, even his elbows. It was clear he had never had a lesson, yet he produced this wonderful version of Don't Cry For Me Argentina."

Mr Ockleford, a music psychologist and then head of music at Linden Lodge School for the blind and intellectually impaired, realised at once that the child frantically bashing keys was a prodigy. Today, at 27, Paravicini is acknowledged as one of only 23 autistic savants in the world. He is one of those rare people with severe learning difficulties, who is a genius in one particular area.