Russ Slater has been writing about this in The Wire a lot, and lot's of it is pretty great stuff. I don't know know much about it, and I'm not that good at describing music so just get stuck in to the comp + these more knowledgeable writers

http://www.soundsandcolours.com/articles/brazil/sounds-and-colours-presents-nossa-cara-new-sounds-of-sao-paulo-in-partnership-with-brasil-music-exchange/
http://www.thewire.co.uk/details/contributors/?contributor=688
http://ontheroadtofindout.com/
http://bmabrazil.bandcamp.com/