How do I move from 'tourist Swahili' to catching regional slang in Bongo Flava music?

I live in Tanzania and I can handle basic daily transactions, but when I try listening to local music, it sounds like a completely different language. I'm stuck on this listening plateau where I understand the words but not the context because of all the slang and speed. Any recommended strategies to bridge the gap between classroom Swahili and the way it's actually spoken on the streets of Dar?