Which of the following is a low-pitched drone instrument used in Australian Aboriginal music?

The didgeridoo is recognized as a low-pitched drone instrument that has significant cultural importance in Australian Aboriginal music. Traditionally crafted from eucalyptus trees hollowed out by termites, it produces a deep, resonant sound that is often used in ceremonial settings and storytelling.

The low pitch of the didgeridoo allows it to create a continuous drone, which is a key characteristic of its sound. This droning effect provides a musical foundation upon which other instruments or vocalizations can layer, making it central to many Aboriginal music performances.

In contrast, the bull-roarer, while a traditional instrument, produces sound through whirling and is not characterized as a drone instrument. The gum and leaf refers more to a form of percussion and sound effects rather than an instrument capable of creating sustained drone pitches. The pipa is a traditional Chinese plucked string instrument, unrelated to Aboriginal music traditions. Understanding the unique qualities and cultural contexts of these instruments helps to clarify why the didgeridoo stands out as the correct choice.