Surdo

The surdo is a large bass drum used in many kinds of Brazilian music, such as Axé/Samba-reggae and samba, where it plays the lower parts from a percussion section.

Surdo sizes normally vary between 16" or even 26" or even 29" diameter. In Rio de Janeiro, surdos are generally 60cm deep. Surdos used in the northeast of Brazil are commonly more shallow (50cm deep). Surdos may have shells of wood, galvanized steel, or aluminum. Heads may be goatskin or plastic.

A Rio bateria will commonly use surdos that have skin heads (for rich tone) with aluminum shells (for lightness). Surdos are worn from a waist belt or shoulder strap, oriented with the heads roughly horizontal. The bottom head is not played.