Bomba is a musical expression created in Puerto Rico at the end of the 17th century, by West Africans and their descendants who worked the colonial sugar plantations along the coast of Puerto Rico. Through fiery drum rhythms and improvised dance, the cane workers released feelings of anger, resistance, and sadness about their condition. It was at "Bailes de Bombas" (Bomba Dances) where baptisms and marriages were celebrated, and rebellions planned. For this reason, celebrations were only permitted on Sundays and Feast Days. At Bailes the Bomba, the sounds of drums called "barriles," typically made of empty codfish or rum barrels, drew the crowd into a circle. Dancers took turns challenging the drums, creating a dialog with their movements that the solo drummer answered. It is said that women bomba dancers would typically dance with their skirt raised, showing their slips, to ridicule the attire worn by plantation ladies.