Observing the British military brass bands in the 19th century, Xhosas and Zulus imitated the bass drum types, the present modern Xhosas Igubu and Zulus Isigubu’ (Dave Dargie, 2015). The Sotho version of the drum is called Sekupu and it was originally a wooden drum.

‘Before the European influence, the instrument “was a wooden drum made from a hollowed tree trunk sculpted into a cylindrical shape. A stretched cow or goat skin was used on both ends‘ (Levine, 2005).

The arrival of British marching brass bands inspired the use of tin vessels that were readily available. The modern drum was now light to carry while playing and gave a different sound.

‘Igubu drum is beaten with short, padded sticks or pieces of wood or rubber. The instrument is played on various occasions and for a variety of ceremonies, particularly in African churches’ (Levine, 2005)

References:
Dargie, D. (2015). Cracking the Rhythm Codes in the Music of the Lumko District. South African Music Studies, vol 34/35, pp.171-204.
Levine, L. and Caplan, A. (2005). The drumcafe’s traditional music of South Africa. Johannesburg: Jacan Media, pp.81 – 83