“A new study shows that when musicians play along together it isn’t just their instruments that are working together, it is happening at the brain wave level also. The research details how EEG readouts from pairs of guitarists become more synchronized, a finding with wider potential implications for how our brains interact when we do….
“The brains’ frontal and central regions showed the strongest synchronization patterns, as the researchers expected. However the temporal and parietal regions also showed relatively high synchronization in at least half of the pairs of musicians. The regions may be involved in processes supporting the coordinated action between players, or in enjoying the music.”
I take it to mean that speaking music not only incorporates most of the brain, but also that the reflection of the sounds is similar between musicians.