... or How Brain Disorders causes mysterious music hallucinations. Janet Dilbeck clearly remembers the moment the music started. Two years ago she was lying in bed on the California ranch where she and her husband were caretakers. A mild earthquake woke her up. To Californians, a mild earthquake is about as unusual as a hailstorm, so Dilbeck tried to go back to sleep once it ended. But just then she heard a melody playing on an organ, "very loud, but not deafening," as she recalls. Dilbeck recognized the tune, a sad old song called When You and I Were Young, Maggie. Maggie was her mother's name, and when Dilbeck (now 70) was a girl her father would jokingly play the song on their home organ. Dilbeck is no believer in ghosts, but as she sat up in bed listening to the song, she couldn't help but ask, "Is that you, Daddy?" She got no answer, but the song went on, clear and loud. It began again from the beginning, and continued to repeat itself for hours. "I thought, this is too strange," Dilbeck says. She tried to get back to sleep, but thanks to the music she could only doze off and on. When she got up at dawn, the song continued. In the months to come, Dilbeck would hear other songs. She heard merry-go-round calliopes and Silent Night. For a few weeks, it was The Star-Spangled Banner. The music often began when she lay down for a nap, or when she drove her car, and would last for hours. Like most people, Dilbeck knew what it was like to have a song stuck in her head, but this was different. The music sounded as vivid as that coming out of a radio or an orchestra pit. The only way she could make the music stop, she found, was to play the radio. "Fight fire with fire," she thought. For the most part, Dilbeck kept her perplexing condition to herself. And the melodies were more than just annoying; they had a strangely sinister quality. Once she began to hear a song -- even if it was one of her favourite pieces by Chopin -- she could no longer bear to listen to a real version of it. Dilbeck endured this mystifying condition on her own for months, until she paid a visit to a San Francisco doctor. She had come to see him about her Lyme disease, which had plagued her since 1993. As they reviewed her symptoms, she told him about the songs. Her doctor informed her that she had a little-known medical condition called musical hallucinosis. She belonged to a small but significant number of people who heard music that simply wasn't there. Read the full article hereCarl Zimmer