What is "imbongi"

Imbongi was the second release by the South African isicathamiya group Ladysmith Black Mambazo. It featured songs such as "Izinkomo Zikababa" ("Our Father's Cattle"), and "Sengikhumbule Nomathemba", which was a follow-up song to a previous Mambazo recording, " Nomathemba" (the name of a girl, "Hope").