Here is a picture of an African drum called a “Djembe”.
The Djembe drum is based on a cylinder or column that can be felt within the human body.
Here is a picture of a human body.
The cylinder or column that can be felt within the human body is located approximately as shown in this picture.
Then a picture replacing the cylinder on the human body with the Djembe.
It is intriguing to note the Djembe actually fits the shape of the human body a little bit better than the single column that can be felt within the body. The bottom of the Djembe is narrow like the legs held together are narrow,
while the top of the drum widens out to match the wider shoulders of the human body.
The actual purpose of the Djembe drum is to develop and strengthen the cylinder within the body. The making of music is incidental.
Holding the drum in front of the body subtly makes the body conform to the circular shape of the drum. The body conforms to the shape of the drum because it is soft while the drum is hard. Over months and years of playing, those subtle sensations make the complex shaped human body feel more like a cylinder.
The body does not just feel like a cylinder internally. As the cylinder inside the body strengthens the movement of the body will change so the individual’s movements look like those necessary to move a cylinder around, and not the movements necessary to move the complex shaped human body around.