The Shamanic drum represents Mother Earth, pregnant with the life-giving energies that she so benevolently gives to us, and bring the Earth alive with her energies. The drum is also symbolic of the Earth bringing us from the physical realm to the divine realm where everything is connected.
The chosen member of a tribe who played a drum would have been the Shaman, using the drum with dance and chants to go into a trance, and thus the lower realms. Shamans were healers, givers of guidance, and communicators with the world of spirits, totems, and planes. Equilibrium of the tribe was maintained because of the universal life force energy that would emit from the drum when the Shaman played it.