The document lists and describes various musical instruments used by the Aztecs, including flutes made of clay and wood called tlapitzalli, ocarinas called huilacapitztli, clay whistles called chichtli, rattles and shakers called ayacachtli, rasps called tzcahauztli, gourd water drums called bubalek, hand drums, gourd trumpets, ankle shakers called atayotls, conch shell trumpets called atecocolli, two-toned carved wooden slit drums called teponaztli, large vertical upright drums called huehuetl, turtle shell instruments called ayoti, frog