The air you breathe / by Frances de Pontes Peebles.

Enhanced descriptions from Syndetics:

Some friendships, like romance, have the feeling of fate.

Skinny, nine-year-old orphaned Dores is working in the kitchen of a sugar plantation in 1930s Brazil when in walks a girl who changes everything. Gra a, the spoiled daughter of a wealthy sugar baron, is clever, well fed, pretty, and thrillingly ill behaved. Born to wildly different worlds, Dores and Gra a quickly bond over shared mischief, and then, on a deeper level, over music.

One has a voice like a songbird; the other feels melodies in her soul and composes lyrics to match. Music will become their shared passion, the source of their partnership and their rivalry, and for each, the only way out of the life to which each was born. But only one of the two is destined to be a star. Their intimate, volatile bond will determine each of their fortunes--and haunt their memories.

Traveling from Brazil's inland sugar plantations to the rowdy streets of Rio de Janeiro's famous Lapa neighborhood, from Los Angeles during the Golden Age of Hollywood back to the irresistible drumbeat of home, The Air You Breathe unfurls a moving portrait of a lifelong friendship--its unparalleled rewards and lasting losses--and considers what we owe to the relationships that shape our lives.