“Show” is not the best word. Thinking about African Diasporic music and the issue of the pulse, I was reminded of the issue of acquisition vs learning. Critics of Krashen rightly say that there is no empirical way to demonstrate acquisition as opposed to learning while those of us who recognized the “feeling” of acquisition understand perfectly what Krashen is talking about. But how do you show it?
The pulse in Diasporic music is clearly there and can be easily demonstrated but not in a scientific manner. Two procedures: put on music with the pulse (TBD by who?) and ask a Diasporic person to dance to it and then put on a similar piece without the pulse and ask them to dance to it. Usually, within a few bars or moments they will sit down, finding the music undanceable.
The second way is to take the hand of a person who does not recognize the pulse or “the beat” as many call it incorrectly and pat out the pulse with their hand (if they will let you; some people are extremely resistant to this for some reason).

Aug. 8, 2019 Addendum I just read recently in Simha Arom’s African Polyphony and Polyrhythm that what can happen is as you listen to a performance, somewhere in the background someone will suddenly begin clapping. That clap marks the beat. So I found a piece of Ogene Igbo music where a flute comes in and there is there is nothing to mark the beat until suddenly some rattles kick in. So you can pat out the beat for someone and have them listen to the piece and then note how when the rattles come in they are right on the same beat you are marking.