Kenyan Hip Hop is the most mature, started in the 90's Kenyan hip hop mashed up formed a bwat called Boomba or Kapuka. Pioneered by Kleptomaniacs, E-Sir, Gidigidi,Kalamashaka, K-south Abbas then came Necessary noiz( Wyre, Nazizi) Redsan, Nameless, Prezzo, Cannibal, Bamboo, Maddtraxx, Nonini etc.
Music producers too were big featuring big names like Tedd Josiah, Ogopa deejeys(which has presence in 5 African countries) Calif records(which came up with Genge(type of music))
Up to now there are big names of underground HipHop artistes which you never hear them on the limelight they do Cyphers, Freestyles, rap battles, they hardly record their music. Kina Johnny Vigetti, Kevo Mamba etc
Then came Urban Hip hop featuring likes of Camp Mulla, Raj, Khaligraph, Octopizzo, Rabbit, STL
It's very interesting how Kenyan music grew.