Surdos

Surdos are a family of large Brazilian bass drums used primarily in samba and related percussion ensembles. In a samba bateria, surdos provide the low-end pulse that anchors the rhythm and guides the other percussion parts. The term surdo is used in the plural form as surdos when referring to the instruments collectively.

Construction and tuning: Surdos are typically two-headed drums with a wooden or ply shell and metal hardware. The heads are usually made of animal skin or synthetic material and are tensioned by laces or mechanical hardware. The drums are large in diameter and are tuned so that each surdo contributes a distinct pitch within the ensemble’s overall rhythm. Surdos may be mounted on stands or carried by players, and tuning is adjusted to suit the musical arrangement and the acoustics of the performance space.

Playing technique and roles: Surdos are struck with sticks or mallets, usually on the center of the head to produce a deep, resonant voice. In many baterias, surdo parts are divided into distinct lines: surdo 1 (the lead), surdo 2 (the secondary pulse), and sometimes surdo 3 or additional surdos that provide accents and subdivisions. The patterns emphasize the downbeat and interlock with other sections such as caixas, repiques, and baquetas to form the overall samba groove.

History and influence: The surdo developed within Brazilian samba ensembles in the early 20th century and became a defining element of the samba school drum corps. Today surdos are used in a wide range of Brazilian percussion groups and have influenced percussion ensembles worldwide.