In Brazilian samba, a distinct deep rhythm is set by special drums. The surdo drum is the bass drum of Brazilian samba. The body of the drum is made of wood or metal, and the membrane is made of plastic or leather. The striking moment is created using a stick with a soft tip and the hand, which mutes the sound in between; sometimes, two beaters are used.

There are three main types of surdo: the largest gives the strongest beat – the surdo marcação. The medium-sized one adds shades and complements the rhythm of the large one – the surdo resposta. The smallest, which provides variation to the main beat, is the surdo cortador.

In fact, there can be more than a dozen of these drums in an orchestra, as each of them has its role. In small orchestras, the main thing is to have maracas, which can replace missing drums, even though this complicates the rhythm. The surdo is most commonly used in carnival music.