The drumming is typically accompanied by singing, usually in Haitian Kreyol. These songs are often structured around a call and response, with a soloist singing a line and the chorus responding with either the same line or an abbreviated version. The soloist is the "hungenikon", who maintains the rhythm with a rattle. Lyrically simple and repetitive, these songs are invocations to summon a lwa. As well as drumming, dancing plays a major role in ritual, with the drumming providing the rhythm for the dance. The dances are simple, lacking complex choreography, and usually involve the dancers moving counter-clockwise around the poto mitan. Specific dance movements can indicate the lwa or their nation being summoned; dances for Agwé for instance imitate swimming motions. Vodouists believe that the lwa renew themselves through the vitality of the dancers.