Sometimes you have to learn to sing before you can speak.

Four years ago, Bill Forester of Bay Village, Ohio, suffered a massive stroke on the left side of his brain and lost the ability to speak. He was in his early fifties, and his doctors told him he might never walk or talk again.

Aphasia is one of the most devastating results of a left-brain stroke. Bill says he felt trapped inside his head. He knew what he wanted to say, but couldn’t get the words out.

Bill's aphasia was even more frustrating because he had made his living with words. He was an adjunct professor at a local college. Today, four years later, he can once again say, "I love to talk."

It was a long road to get here. He has been guided by a speech therapist at the Cleveland Clinic, Lisa Gallagher, who uses music to retrain the brain.

"Language is on the left, music is on the right," she explains. "So music can be used to help retrain the left side of the brain."

In most people, the speech centers are on the left side of the brain. Through music, the healthy right brain can help pick up some of the work that the damaged left brain can no longer perform.

In their therapy sessions, Bill and Lisa sing and use instruments like guitar and piano. Along with the language centers, these exercises help Bill with fine motor movements on the right side of his body (also damaged by a left-brain stroke) and strengthen his diaphragm.

Bill's wife Lori Forester was the first to notice the difference. "His voice sounded more natural," she says. "it just sounded like Bill again."

But retraining an adult brain is slow work. Bill had to relearn the alphabet. It was eight months before he could even ask for a glass of water.

Persistence is paying off. Bill says he is determined to be "whole" again, no matter how hard he must work. It is not just his speech that is returning. The man who was told he might not walk or talk again is now running marathons.