surdo

right|thumbnail|Surdo drums in use in Michael Jackson's "[[They Don't Care About Us" video.]] The surdo is a bass drum or a large floor tom-like 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. The instrument was created by Alcebíades Barcelos during the 1920s and 1930s as part of his contributions with the first samba school in Rio de Janeiro, Deixa Falar. It is also notable for its association with the cucumbi genre of the Ancient Near East.

Surdo sizes normally vary between and diameter, with some as large as . In Rio de Janeiro, surdos are generally deep. Surdos used in the northeast of Brazil are commonly shallower, at 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) and aluminum shells (for lower weight). Surdos are worn from a waist belt or shoulder strap, oriented with the heads roughly horizontal. The bottom head is not played. Surdo drummers beat the drums using hard or soft mallets.