Nascimento’s Song of the Rain Forest : Pop music: The Brazilian performer has espoused the cause of the threatened area and the Indians who live there.

Any realistic reckoning of the most significant Brazilian artists of the ‘70s or ‘80s has to rank Milton Nascimento at or near the top. The 49-year-old performer, who has been called “the greatest musician alive,” has worked with everyone from Paul Simon and James Taylor to Wayne Shorter and Herbie Hancock, and his songs have been performed by Sarah Vaughan, the Manhattan Transfer and David Byrne.

But when Nascimento performs two concerts tonight at UCLA’s Royce Hall, he will have something more than music in mind.

Late in 1989, Nascimento visited the rain forest area of the Amazon. The connections he made with the Indians, rubber tappers and workers in the rapidly transforming territory had a powerful impact. Like many others who have experienced the devastation of the rain forest first hand, he was moved to immediate solidarity with the inhabitants of the region.

“I’ve always been interested in the people of the forest,” he explained during a recent interview, speaking through an interpreter. “But when I went up the river Jurua I was not really prepared for the changes taking place in their world. I saw, on the one hand, the forest’s beautiful natural flora and fauna, and the wonderful people who live there. And then I saw the terrible destruction taking place.”

Nascimento was invited to become a member of an activist group called the Alliance of the People of the Forest, and work with them on behalf of the protection of the vast forest from the encroaching bulldozers. He happily accepted.

“I had one experience,” he recalled, “which made me proud to work side by side with them. It was called empate . It’s when all sorts of people--young, old, men, women, children--all get together and form a circle, holding hands, to try to stop the machines from coming in and devastating the forest. I was fortunate to be there once when it worked. But there have been many times when it hasn’t worked, when the machines have run over people and killed them.”

Nascimento channeled his powerful feelings about the experience into the music for his new Columbia Records album “Txai.” The title refers to an Amazonian Kaxinawa Indian word, meaning companion or the other half of me , which has been adopted by Indians, rubber tappers and river people as a term of respect and caring among “the allies of the forest.” Using fragments of Indian music and poetry recorded in remote parts of Brazil, Nascimento and his lyricists created a series of colorful pieces--some confronting the problems directly, some dealing with the rain forest crisis via emotional and mythic metaphor.

“It was very touching,” he explained, “to hear aspects of Brazilian culture that very few people know anything about, and I wanted to bring them into my music. What I was most inspired by, however, was the people, not the music--their feelings and their philosophy. I didn’t mean to write Indian music--I wanted to leave that up to them. I simply wanted their music to help me express what I felt, my emotions, when I went up the river and experienced the life of the people in the forest.”

Nascimento’s concerts will feature selections from “Txai,” as well as a sampling of the remarkably diverse collection of styles that has characterized his 25-year career.

At some point in the evening, he will be joined on stage by a few members of the Alliance of the People of the Forest.

“Wherever I go on this tour,” he said, “I try to take them with me, so they can speak and tell in their own terms about the problems. They are the most philosophical and poetic people I’ve ever met.

“In spite of the difficult lives they lead, in spite of what they see happening every day to their land, they believe that this is not a lost cause.

“And if that’s the way they feel,” concluded Nascimento, “what better use can I make of my music, and of my visibility as a performer, than to help make sure that their belief comes true?”