The biggest surdo called the primeiro, plays on beats 1 & 3 and sets the tempo for the band. Combined with the Surdo 2, these are are called Marcacao (meaning “marking” as in “marking time”), because they mark the beat.
The Surdo Resposta (meaning response) or Surdo Segunda responds to the First Surdo & plays beat 2 & 4. Together the Surdo 1 & 2 create a “heartbeat.”
The Third Surdo or Small Surdo plays the samba reggae “off beat” and other syncopated rhythms. It cuts in between the beats of the two big drums with more complex rhythms and leads the dancing movements in the band.
Has a high pitched “metallic” tone and makes the calls to the other drums.
The “engine” of the band, similar to a snare that can be found in a rock band.