Vibrations and people don’t have fixed edges. We overlap, like circles in a Venn diagram. Once we say this, it seems obvious. Of course, we are always being affected by each other. And yet, do we sing as though we understand this is happening?

If you put a stringed instrument near a compatible vibrational source, the strings will tend to tune themselves to that source. Entrainment means the tendency of any vibration to readjust and match other vibrations nearby. People do this too! Social entrainment can be observed in the way that groups of friends may tend to move