Cerebral networks for spontaneous and synchronized singing and speaking.

Singing in unison is usually easier than singing alone, but the neural mechanism underlying these two contrasting modes of singing remains unknown. We investigated neural correlates of singing by a functional magnetic resonance imaging study focusing on the capacities of spontaneity and synchronization and compared them with those of speaking. The left inferior frontal gyrus appears important for self-generation of text in singing and speaking without auditory input, whereas the left posterior planum temporale plays a key role in synchronizing both text and melody, in combination with the bilateral inferior parietal lobule for singing along, and with the left angular gyrus for speaking in chorus. These findings indicate that text and melody are not processed symmetrically or parallel in singing a well-learned song.