When your favorite band rocks out on stage, they're coordinating more than their jams and their dance moves. A new study suggests that pairs of guitarists playing the same melody simultaneously have significantly similar brain waves. The research, published today in the online journal BMC Neuroscience, is the first to measure the brain activity of more than one musician playing at the same time, and may have broader implications regarding how our brains interact when we coordinate actions with other people, like matching our walking speed with another person, playing in a band, playing sports, and dancing. The findings may also apply to social bonding behaviors, like coordinated gazes between a mother and child or between partners.

In the study, researchers from the Max Planck Institute for Human Development in Berlin tested eight different pairings of professional guitarists over a total of 60 trials. For each pair, simultaneous EEGs, which measure the brain's electrical activity, were recorded before and while they played an identical melody -- a modern jazz-fusion piece called "Fusion #1" by Alexander Buck. Before each trial, a metronome playing over a loudspeaker counted at least four beats before the guitarists began to play.

Both audio and video recordings for each trial allowed researchers to observe the coordination between the musicians playing their instruments and their respective brain waves. The video shows three trials from one of the pairs, guitarists A and B. The EEG recordings from six different electrodes, which were attached to the guitarists' heads, are denoted by F3, Fz, F4, C3, Cz and C4, and the audio data from the microphones connected to each instrument are micA and micB.

Over time, the similarities between the brain waves increase significantly, both during the initial metronome beats and during the melody. According to the researchers, it is unclear whether or not the brain wave synchronization plays a causal role in the coordination between the guitarists, or if they are simply reflective of the movements both musicians are going through as they play the same song -- the researchers hope to clear this up in future studies. In the meantime, we'd like to see the brainwaves of someone trying to keep up with this kid.