Embu – bordered to the East by Kitui, Kirinyaga to the West, Machakos to the South and Tharaka Nithi to the North – is often regarded as one of the dullest counties in the country, musically speaking.

For decades, a soft-touch style of soul music has found a strong Chicano and Latino audience in Southern California. A record label based there is helping it bloom. For decades, a soft-touch style of ...