A bembé is a party for the orishas. During a bembé the orishas are praised, saluted and entreated to join the party through `mounting' one of the priests or priestesses in attendance. This is done through a confluence of the song, rhythm, and movement, all calling to the orisha in such a way that the orisha will recognise themselves in the lyrics, rhythms and dances as they have been performed for them for perhaps thousands of years.
The rhythms play an important part of the equation and the drummers practice assiduously for years to be able to play the intricate rhythms correctly. This is important since the drums are actually speaking to the orishas as the Yoruba language is a tonal one and the drums are tuned in such a way as to play the tones of Yoruba speech. For this reason some rhythms are never played unless it is in religious context as it would offend the orisha. These rhythms are actually prayers to the deities with each orisha having its own rhythms associated with them.
Dance also becomes prayer in the religious context of a bembé. The movements of the dances are the same motions associated with the orishas for thousands of years. As with the rhythms played on the drums, each orisha has its own dances with Yemayá's dance emulating the motion of the waves, Ogún's chopping with his machete, Oshún's portraying her primping in front of her hand held mirror, etc. Therefore these movements become more danced prayers than what the Western European would refer to as dance.
Everything present at a bembé whether it is song, dance, rhythm or colors used, becomes part of an intricate fabric of prayer saluting, praising and calling to the orishas and asking them to be present and calling the orishas to be with us.