Washington ? Sounds from the radio slip into a melody and suddenly your mind skips back to an evening of moonlight and romance and happy times. It happens to everybody, but until now science was unsure just why.

A new study by researchers at Dartmouth College in Hanover, N.H., suggests that recalling that melody is the job of a part of the brain known as the rostromedial prefrontal cortex. It is the part that remembers music and is even able to recognize a sour note in the midst of a familiar tune.

A team led by researcher Petr Janata of Dartmouth’s Center for Cognitive Neuroscience explored the mind’s memory for tunes by studying the brains of eight musicians as they listened to a bit of original music.

Using functional magnetic resonance imaging, which detects the part of the brain active in response to specific stimuli, they found that the ability to recognize music is contained in a centrally located area just behind the forehead.

Janata said that part of the brain also played a key role in learning and in the response and control of emotions.

“Our results provide a stronger foundation for explaining the link between music, emotion and the brain,” Janata said.

In the study, published today in the journal Science, eight people who had studied music for at least 12 years listened to the music and were asked to pick out specific tones and to detect notes played by a flutelike instrument instead of a clarinet, which had dominated the music. As they performed these tasks, the functional MRI tracked which parts of the brain were active.

The researchers reported that the brains of each of the subjects tracked the sounds in a slightly different way each time the music was played. This may be the reason the same music, in different times, may prompt different emotions.