What would be a word describing the connection between two seemingly unconnected things?

I'm looking for a word that describes the invisible connection between seeming unconnected things. Like the area below the surface connecting an island chain, but that could potentially relate to people/ relationships as well. The closest things I've thought of is entanglement.

ie. a single work for degrees of separation

looking for something with more of a pulse than tie or bond. Like synapse, but not just for nerves.

Sentence: Everyone in the room was working independently, but could feel each other's humanity through _____.

Solution 1:

Synchronicity

The simultaneous occurrence of events which appear significantly related but have no discernible causal connection.

ODO

As the show progresses, one starts to get the feeling the lightning is happening in synchronicity with the music.