“Asa Branca” (white wing) is named after the picazuro pigeon of Brazil's dry Northeast, the sertão. When drought burns the land, even the asa branca flies away — and so does the singer, leaving his home and his love, Rosinha, to look for work in the south. He promises that when the rain returns and the land is green again, he'll come back.
Luiz Gonzaga, the “King of Baião”, recorded it in 1947 with his accordion, and it became the unofficial anthem of the Northeast, sung by millions of migrants who made the same journey.
The Portuguese is simple and rural, sung slowly. Vocabulary of nature and leaving — the drought, the rain, the land, to go away, to come back — makes it a beautiful A2 song.