Originally, the Surdo is a derivative of the bass drums played in European Street/brass bands, while, in terms of rhythm, its musical role is directly linked to African drumming traditions.
In samba percussion ensembles (baterias), its function is to emphasize the main beat (pulsation) and bring variations to the second beat of a 2-beat, basic pattern.

Surdo is played with mallets; generally with one mallet and one bare hand to modify the sound length and pitch by pressing the drum head. Mallets' ends are often thick and soft in order to make the impact with the head and the resulting sound softer.

This range of professional, aluminum surdos created by Contemporânea has the distinctive feature of having shorter shells than other conventional surdos.
These Axé surdos are particularly efficient in producing more mufled, overtone-free sounds (an effect that can be accentuated by using a napa head, i.e. a sheet of Naugahyde placed across a standard drumhead).
Relatively light and small (16 X 22 in), they are mostly used to play samba-reggae and its derivatives, allowing the craziest choreographic performances!

NB: unlike the model pictured, the available model hasn't got fasteners fixed to its shell.

Diameter : 22 in
Head : synthetic
Shell : aluminium
Tension rods : 8
Weight : 6.8 kg
Delivered with a tuning spanner