Bullroarer / Board – Wood – Yoruba – Nigeria

Old wooden Yoruba board / bullroarer from Nigeria.

The bullroarer, rhombus, or turndun, is an ancient ritual musical instrument and a device historically used for communicating over great distances. It consists of a piece of wood attached to a string, which when swung in a large circle produces a roaring vibration sound.

A bullroarer consists of a weighted airfoil (a rectangular thin slat of wood about 15 to 60 centimetres (6 to 20 in) long and about 1.2 to 5 centimetres (0.5 to 2 in) wide) attached to a long cord. Typically, the wood slat is trimmed down to a sharp edge and serrations along the length of the wooden slat may or may not be used, depending on the cultural traditions of the region in question.

The cord is given a slight initial twist, and the roarer is then swung in a large circle in a horizontal plane, or in a smaller circle in a vertical plane. The aerodynamics of the roarer will keep it spinning about its axis even after the initial twist has unwound. The cord winds fully first in one direction and then the other, alternating.

It makes a characteristic roaring vibrato sound with notable sound modulations occurring from the rotation of the roarer along its longitudinal axis, and the choice of whether a shorter or longer length of cord is used to spin the bullroarer.

Provenance: former private collection from the Netherlands.