Can you speak Portuguese, or are you Brazilian and can translate this for me?

Question

I need help, can anyone who speaks Portuguese please tell me what these people are singing about? They are the lovely Brazilian people i met in Sydney, though we couldn't understand one another, theses are the videos i have of them with us on the train.

http://www.youtube.com/watch?v=OECfZw7XFqU

http://www.youtube.com/watch?v=d4yfGZdib9c&NR=1

http://www.youtube.com/watch?v=Mq3lMCZPp2c&feature=related

Also if you know the names of these songs that would be GREAT! Thank you!!

Answer 1

First video - carnival song, from the samba school's parede in 1993, you can find the lyrics here http://letras.terra.com.br/salgueiro-rj/474186/    

second video - http://letras.terra.com.br/bruno-e-marrone/195710/ A song from Bruno e Marrone. They're very popular in Brazil.

Third video  -  Trem das onze (The 11pm train) It's a classical. http://letras.terra.com.br/adoniran-barbosa/173850/