Music is always a good way of get the noises, expressions and idioms of le language that we are learning. At the same time, you get some hints of the culture. Try not to read the lyrics the first three or five times, but to write by yourself. Then you can check it, and search for unknown things.

Here are some suggestions. Of course, there are much more (please don't hesitate in adding more down here!):
1. Pais tropical (Jorge Ben)
2. Construção (Chico Buarque)
3. Chocolate (Tim Maia)
4. Que país é esse? (Legião Urbana)
5. Vambora (Adriana Calcanhotto)

EXTRA PRO: Conversa de botequim (Noel Rosa)