'Bombo legüero' is an Argentine drum traditionally made of a hollowed tree trunk and covered with cured skins of animals such as goats, cows (leather) or sheep; legüero signifies that one could supposedly hear it a league away.
[1] It derives from the old European military drums, and uses a similar arrangement of hoops and leather thongs and loops to tighten the drumheads, which are usually double.
The drumheads are made of the skins of animals such as cows, sheep, or guanacos.
The player's hands hold a soft-headed mallet and a stick, which strike drumhead and wooden rim in alternation.
The bombo serves as a combination of bass and percussion, not just maintaining the meter, but evoking an elemental, visceral response.