Kiriba is a style of Son from a different area of Cuba. It mostly originated in the Baracoa area, which is also where the Changüi was created. In fact where the fusion of Kiriba and Nengon takes place is where Changüi is invented. And where Nengon evolved, it evolved into Son.
Like Nengón, the Kiriba's identifying feature is the constant alternation of improvisational verses sung by a soloist and a chorus. Generally Kiribá is played with tres, bongós, maracas, güiro, and marímbula, (this ensemble is similar to the changüi). Nengón and Kiribá are practiced in the mountain regions of Santiago de Cuba and Guantánamo.
In my book "El Tres Cubano", I show in detail examples of the tres parts in both Nengon and Kiriba. I also have examples of both played in a modern ensemble context.
Con Sabor Al Guaso
Official Retrospective Of Cuban Music