http://en.wikipedia.org/wiki/Teponaztli
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A drawing from the 16th century Florentine Codex showing a One Flower ceremony with a teponaztli (foreground) and a huehuetl (background).
Two Aztec teponaztli. The characteristic "H" slits can be seen on the top of the drum in the foreground -- note that one of the tongues is longer than the other. These drums in the American Museum of Natural History are approximately 2 feet (60 cm) long.A teponaztli is a type of slit drum used in central Mexico primarily by the Aztecs. Meaning "wooden drum" in the Aztecs' Nahuatl language, the teponaztli was made of hollow hardword logs, often fire-hardened.
Like most slit drums, teponaztli have three slits on their topside, cut into the shape of an "H". The resultant tongues are then struck with rubber balls on mallets, which were often made of deer antlers.[1] Since the tongues are of different lengths, or carved into different thicknesses, the teponaztli produces 2 different pitches, usually a third or fourth apart.
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