This is one of my favorite songs. I have learned to sing it in both English and Brasilian Portugues'. My brother Steven's wife, Luciana, is a Brasileira from Goiânia, near the Capitol Brasilia. I have some Pimsleur Language Program tapes that I've studied and find the language so beautiful.
If you've seen my two videos and heard my naturally twangy voice you may ask yourself, "Is this guy crazy?" Perhaps so, but I have a few months before the next open mic at the Ukulele Club of Santa Cruz and I'm going to give it my best to be ready to perform. [Should I have a plan "B" ready?]
As I was studying, I also listened to some music to get a better feel for the sound of the language. I became quite fond of Caetano Veloso's slower singing pace and his clear enunciation of words. Here is Caetano with the beloved Tom Jobim.
Here's an excellent CifraClub.TV video of the song on GUITAR but it goes over various aspects of the song including rhythm. Unfortunately, it is in Brasilian Portugues' -- ah, but you can get some of the flavor of the language.