A sekere is made from a dried gourd covered in a loose, hand strung net of beads or cowrie shells, played by shaking, striking against the hand, or twisting so the beads slap rhythmically against the gourd's outer surface, producing a bright, textured percussive sound distinct from an enclosed rattle. Within Yoruba religious practice, the sekere is used in the worship of specific orishas, and particular rhythms played on it, together with accompanying songs, are understood to call and honour individual orishas by name, a function documented in Bascom's and Idowu's scholarship on Yoruba religion and divination, which situates percussion and specific rhythmic patterns as integral, non optional elements of correctly addressing a given orisha rather than as generic musical accompaniment layered onto worship from outside it.
The instrument's construction itself, requiring skilled netting of beads at a specific density to produce the right sound, is a recognised craft within Yoruba ritual material culture in its own right. Skilled sekere players are recognised within their communities much as skilled drummers are in other West African percussion traditions, since correctly summoning a given orisha depends on getting the associated rhythm exactly right rather than approximating it.
Sources Ifa Divination: Communication between Gods and Men in West AfricaWilliam Bascom with Olodumare: God in Yoruba BeliefE. Bolaji Idowu