Surdo

This is a wood or metal drum with heads on both sides. The heads can be either calf-skin or plastic. It is played with a mallet in one hand and the fingers and palm of the other hand. The mallet is made of either felt or natural animal hide (or some other type of covering) around a wooden beater. While one hand strikes the drum with the mallet, the other mutes and/or plays some supportive or decorative rhythms around the main pulse. Surdos are most commonly and traditionally used in Escolas de Samba where they can have as many as 25 - 30 surdos in a group of 100 percussionists.