The opening line of “Dreamers,” the new oratorio from composer Jimmy López and librettist Nilo Cruz premiering March 17 at UC Berkeley’s Zellerbach Hall, harks back to the beginning of time, the inevitability of motion, of migration as an element of nature:

“Before the divide of land, before everything and nothing, there was the will to migrate,” it begins.

A single voice — of soprano Ana María Martínez — utters the first word against a backdrop of silence. A singing bowl then rings out at the same pitch, “an enthralling sound calling for our attention for what comes next,” López says, describing these opening moments. Then, when Martínez gets to the word “divide,” a chorus of many voices joins in, a nearly 80-voice choir made up of Bay Area contemporary vocal ensemble Volti and the UC Berkeley Chamber Chorus. The sound then swells with low strings and woodwinds as Esa-Pekka Salonen leads the Philharmonia Orchestra of London in this grand opening for a grand concept.

The world premiere of “Dreamers,” commissioned and presented by Cal Performances, is an operatic take on the experience of so-called “Dreamers,” young undocumented immigrants in DACA, the Deferred Action for Childhood Arrivals program that shields them from deportation, but which is now in flux.

Composer Jimmy López

It’s part of a weekend of concerts March 15-17 at Zellerbach with Salonen, the new director of the San Francisco Symphony, and the Philharmonia. Other concert highlights include Salonen’s 2017 Cello Concerto featuring Truls Mørk,  Stravinsky’s The Firebird, Bartók’s Concerto for Orchestra and works by Sibelius, Bruckner and Schoenberg.

“Dreamers,” López said in a phone interview, was originally supposed to be titled “Dreamer” — no “s” — expressing the unsettled experience of a single young person in the program.

But while developing the work, López, an immigrant from Peru himself, and Cruz, a refugee from Cuba,  interviewed several UC Berkeley students who are undocumented immigrants — some of the more than 500 enrolled at Cal and served by the university’s Undocumented Students Program.

Librettist Nilo Cruz

Cruz and López quickly realized the title needed to be in the plural.

“We try to group these young people with a label, but honestly their experiences couldn’t be more different,” López said. “Some came here when they were babies so they’ve known nothing else and have lived here all their lives. Some came when teenagers, had established identities. Others came from poverty and violence.

“That opened up my eyes,” the Berkeley-based López said. “I hadn’t understood it that way before. Now I have seen that this is about many voices.”

This revelation inspired the format of soprano and chorus, he said, with the music of many voices serving as an “emotional framework” for the message — “an attempt to convey the young people’s anxiety, fear and uncertainty,” he said, now that the program is in limbo.

“Dreamers” was co-commissioned with Washington Performing Arts as part of Cal Performances’ Berkeley RADICAL programming, spotlighting the human side of the current debate on immigration. The premiere is accompanied by public programs, including an artist workshop at the Oakland School for the Arts.

Conductor Esa-Pekka Salonen

The new work marks the second collaboration for Cruz and López, who are already well-known for their operatic adaptation of Ann Patchett’s novel “Bel Canto” for Lyric Opera of Chicago, which was broadcast on PBS’s “Great Performances.”

The “Dreamers” concert will be livestreamed on Cal Performances’ website and YouTube channels for those who can’t attend.

For more information: Tickets range from $40-$125;  510-642-9988 or www.calperformances.org.