Undertanding!

Hello folks...
I´d like to know if any one has some tip or tecnique to hep me improve my listening...i know there are tons here...but the problem is.....i have no problems, (writing), speaking and listening fast when it is personally...however... some musics, movies and tv shows....i need to rewind over and over and o don´t get some words. To have an idea i don´t catch all the portuguese words some times said fastly. It seems wierd, but it is true.