**** Does not sound Brazilian to me. ****
Probably because you stopped listening with Sergio Mendez and Brazil 66. Defining Brazilian music by the Mendez formula is like saying that if it doesn’t sound like the Beatles it doesn’t sound American. Mendez’ music was Brazilian music-lite. That was 1966. 50 years ago! Nascimemto’s music is very much Brazil and is where popular music in Brazil is NOW, not 50 years ago. Familiar theme, isn’t it? Of course, the language is Portuguese; spoken in Brazil. The songs themselves are very Brazilian in their melodic shapes.
I disagree with the notion of “music flow” in this case and I think you short change Brazilian music’s innate value. As great as Hancock is on the record, he simply played on the record. Nascimento composed the music, arrangements, sang the songs and also played on them. Hancock made a huge contribution, but ir was a supporting/accompanying role no matter matter how one looks at it and no matter how well he did it. Different piano player? Might work, might not work as well, probably not, but it would still be essentially the same music. Different composer/singer? Different music altogether.
The music on the record with Hancock is a meeting of the two cultures. Let’s put it this way: would you call it Jazz? I wouldn’t; not that it matters. The songs themselves are very Brazilian in their melodic shapes. Hancock brought the other sensibility to the table. It’s a blend. That’s the point. And it works better than usual.