The large percussion ensemble accompanying a Rio samba school is called the bateria.
A bateria supplies the rhythmic foundation of the parade, using instruments such as surdos, caixas, repiniques, tamborims, cuícas, and chocalhos. Its performance helps maintain the pulse that allows thousands of participants to sing and move together.
The term is Portuguese for “battery” or percussion section. In a samba-school parade, the bateria is one of the core judged elements and is led by a mestre de bateria. The ensemble’s breaks, called paradinhas, can create dramatic pauses and audience interaction.
Bateria is not the same as samba-enredo, which is the theme song performed by the school, or an ala, which is a parade wing. Those elements work with the bateria, but they describe different parts of the presentation.