Researchers have found that brains of musicians playing a duet, even in different voices, are connected. The synchronization of the brain activity in these people occurs in regions of the brain devoted to social cognition and music production.

The idea that the brains of musicians playing the same tune have inter-connected brains was already established by researchers from Max Planck Institute in Berlin in 2009. In the current study, researchers went a step forward to find out if peoples' brains co-ordinated if the guitarists played different voices of the same song instead of same notes. The co-ordination that occurs between musicians isn't by external stimulation but is rather due to the brain working together to play music.

The study included 32 experienced guitarists in duet pairs. Electrical activity in each participant's brain was assessed. The musicians were then asked to play a sequence (from the "Sonata in G Major" by Christian Gottlieb Scheidler) 60 times. Each musician had to play a different voice and one of them had to ensure that they started at the same time and held the same tempo.

Brain activity of the duet showed coordinated brain oscillations, even while playing different voices of the same sequence.

"When people coordinate their own actions, small networks between brain regions are formed. But we also observed similar network properties between the brains of the individual players, especially when mutual coordination is very important; for example at the joint onset of a piece of music," said Johanna Sänger from Max Planck Institute for Human Development in Berlin, lead author of the study.

Subtle differences in brain waves of the musicians that were assessed using electrodes showed who was the leader and the follower among the pairs of guitarists.

"In the player taking the lead, the internal synchronization of an individual's brain waves was stronger and, importantly, was present already before the duet started to play," said Johanna Sänger in a statement. "This could be a reflection of the leading player's decision to begin playing at a certain moment in time," she added.

It's not just music that connects peoples' brain. Researchers say that coordinating actions lead people to start synchronizing brain activity with each other.

"We think that different people's brain waves also synchronise when people mutually coordinate their actions in other ways, such as during sport, or when they communicate with one another," Sänger added.