When Lou Harrison died in February 2003, the 85-year-old composer had lived a full, rich life. After decades in the musical wilderness, he had lived long enough to see his prescient passions — for percussion, world music, alternative tunings, and a return to tonality — accepted and even celebrated by a musical establishment that had for years shunned or ignored them. Widely recognized as one of the greatest composers of the 20th century, he’d garnered commissions, honors, and recordings in abundance; in 2000, Mayor Willie Brown had awarded him the keys to the city at a grand San Francisco Symphony tribute concert.

And yet, Harrison left one major musical goal unfulfilled: a production of the final version of an opera he’d labored over for three decades. On Feb. 16 and 17, Harrison’s final great vision will at last be realized when Ensemble Parallèle presents Harrison’s Young Caesar at the Yerba Buena Center for the Arts.

His pioneering music wasn’t the only aspect of Harrison’s life that was ahead of his time. He was a proud gay man who was out of the closet from his teenage years in San Francisco in the 1930s, and had been active in the city’s groundbreaking gay rights movement since the 1950s.

In the late 1960s, not long after they met, Harrison’s life partner, Bill Colvig, asked him why he had never written a major musical work on a gay theme. Harrison was just then trying to figure out what he would compose for a commission he had been awarded by a new music group in Pasadena. He knew he wanted to write a second opera (his first, Rapunzel, had premiered in the 1950s), and he had long craved to create a puppet opera, an ancient tradition especially popular in 18th-century Europe. Haydn, among others, wrote several, and Harrison especially admired Manuel de Falla’s whimsical Master Peter’s Puppet Show.

When Colvig suggested a gay theme, Harrison, a serious student of history, suddenly recalled reading in Suetonius about the meeting of the teenage Julius Caesar and King Nicomedes of Bithynia while the young Roman was on a vital diplomatic mission in a strategically important part of what is now Turkey. Their subsequent make-love-not-war relationship proved a turning point in the lives of both leaders, as well as their nations.

The East-meets-West theme perfectly suited Harrison’s explorations of world music. He and Colvig resolved to build their own instruments in the tradition of the Indonesian percussion orchestra. Harrison and Colvig’s gamelan, which they began building in 1969, is thought to be the first built in America. It was tuned in modes appropriate to “Eastern” music, then contrasted with Western tunings and instruments. If all that weren’t enough, Harrison wanted to use a kind of recitative style drawn from the Chinese operas he’d seen as a boy visiting San Francisco’s Chinatown, with a narrator in the manner of Greek tragedies, such as The Eumenides, for which Harrison had composed music in the 1930s at Mills College.

After several false starts, Harrison settled on San Francisco playwright Robert Gordon to write the libretto and KQED art director Bill Jones to create the puppets; Harrison himself painted lovely moving backdrops.

But the November 1971 Pasadena premiere of the first version of Young Caesar, conducted by Robert Hughes and featuring a quintet of multi-instrumentalists including Harrison and Colvig, drew mixed reviews. Some listeners accustomed to traditional Western-style opera found the extended recitatives insufferable, the form inscrutable, the puppets inexpressive, the absence of true arias intolerable. The subject matter might also have played a role. “Some of [the critics and audience] didn’t know the old saying about Caesar: every man’s woman and every woman’s man,” Harrison said. “When the Senate was mad at him, they used to hail him as he came in, ‘Hail, Queen of Bithynia!’ ”

Dismayed but not discouraged, Harrison reworked the opera, jettisoning the puppets, adding arias, cutting recitatives, and orchestrating the music for 11 Western instruments, percussion quintet — and live singers. In 1988, that semistaged version premiered in the city of Harrison’s birth, Portland, Ore., with the city’s Gay Men’s Chorus. Again, Harrison felt that the piece needed reshaping, and the opportunity for a definitive version arose a decade later, when the Lincoln Center Festival commissioned a definitive dramatic production with longtime Harrison champions Mark Morris directing and Dennis Russell Davies conducting.

Harrison again embarked on a furious round of rewriting, adding some gorgeous arias and rejiggering some of the other music. But Morris' heavy touring schedule forced his withdrawal, and his replacement, choreographer Bill T. Jones, never quite came to terms with the project. The opera’s chief advocate, John Rockwell, left Lincoln Center to return to The New York Times, costs mounted, and, according to Harrison, the repercussions from the September 11, 2001, terrorist attacks caused a pullback from risky new productions. Harrison received the festival's cancellation letter in 2002 while working with his friend Nicole Paiement on her recording of his Rapunzel with her Ensemble Parallèle.

Harrison was bitterly disappointed. “Right then, I told him, ‘OK, we’re going to make this happen,’ ” Paiement recalls. Harrison never gave up on Young Caesar. He discussed the possibility of a Bay Area production with Paiement, who included several of the new arias on a CD released in 2003. But Harrison died that year, the dream of seeing his final opera staged in its final version unrealized.

But as so often happened with Harrison, whose ebullient love of art, music, and life attracted so many supporters, others stepped in to help complete his vision. Paiement, Gordon, and stage director Brian Staufenbiel had talked to Harrison about the big ideas he wanted to convey. “Bill Colvig had told him that he’d been so wonderful in helping him feel how beautiful it was to be a gay man, why not choose a beautiful love story between two men?” Paiement says. “But although it starts as a homosexual relationship, it goes into matters more universal: about power and the challenges we all face in life. It was good to hear that from him before he passed away, and that guided us.” Harrison had added more arias to give female cameo roles their own songs, and also to balance Nicomedes’ role with Caesar’s. He also cut some of his music, including a dance he never regarded as one of his strongest. But most of what remained to be done was paring dialogue, recitative, and narration.

Some observers regarded parts of the libretto as dated or even campy, but Harrison wasn’t willing to change it without Gordon’s permission. But after Harrison’s death, the librettist worked with the production team to refocus the libretto. “It took me a while to realize,” Gordon explains, “that the basic motifs of the opera were chance and unpredictability, and the need to accept both if one was to survive and grow — a belief both Lou and I shared — whether one is a Roman king or slave, a shrewdly ambitious male courtesan or Caesar’s powerful Aunt Julia, or the King of Bithynia, who is dazzled by young Gaius as Gaius as dazzled by him.”

Now the action takes place in 14 short, connected scenes. Rather than puppets moving mechanically, dance and choreographed movements now animate live singers. Some of the props and visual elements are inspired by the opera’s original incarnation; Paiement hopes to integrate even more of the original features into later, bigger-budgeted productions. While the story, heavily researched by Gordon, hews to historical fact, the design incorporates both modern and historical imagery.

Despite its turbulent — even operatic — production history, the constant that shines through Young Caesar is Harrison’s ravishing music, which melds Eastern and Western influences in his own original, inimitable way. It should appeal to fans of classical music, world music, opera, and anyone else who treasures melodic beauty and musical exploration. But how will it compare to the original version’s striking, cross-cultural juxtapositions of instruments, tuning, and style? No Western string instrument can capture the poignancy of a Chinese zheng (a plucked Chinese zither) playing “Palace Music” as Caesar enters Bithynia. The new production aims to restore some of the original instrumentation, so we'll see whether Harrison’s latter-day attempt to imitate the sound of non-Western music with Western instruments and temperament will be as effective as the original production’s direct contrast of Asian and Western musical forces.

The performers, including a chorus drawn from the San Francisco Conservatory of Music (where Ensemble Parallèle is in residence) and UC Santa Cruz (where Young Caesar will be presented April 3), feature the veteran tenor and contemporary opera specialist John Duykers as the Narrator and SFCM voice professor Wendy Hillhouse as Caesar’s Aunt Julia. For the crucial lead role of young Julius Gaius Caesar, Paiement chose Eleazar Rodriguez, a 22-year-old SFCM student from Coahuila, Mexico.

Rodriguez arrived in the U.S. just last August, auditioned for a chorus part, and found himself in a leading role. He found the untraditional recitatives a bit challenging, but the arias “fit my voice comfortably and they are very beautiful,” he says. Rodriguez relishes playing a character who grows in wisdom in the course of the opera. “He starts as a young man dominated politically by the family, and he grows from being naive to self-assured.” At the opera’s climax, young Caesar faces a tough choice about whether to follow his heart or his ambition. "We all have hard decisions to make,” Rodriguez says. “Sometimes there are certain things you have to do to get what you want, and sometimes that implies sacrifices you have to make.”

The production is sponsored by UC Santa Cruz and BluePrint, the SFCM’s splendid new music series. Paiement, who also directs the SFCM New Music Ensemble and is director of ensembles at UC Santa Cruz, hopes that this production will also inaugurate a new chapter for Ensemble Parallèle, which has brought to light overlooked 20th-century works, presented many American and world premieres, and commissioned more than 15 new works. She hopes the group will further explore contemporary chamber opera.

Toward the end of Young Caesar, Aunt Julia tells her nephew, “Only the dead can afford the luxury of limitless time, Gaius.” Julius’ lover Nicomedes replies, “All our efforts wash into the sea of time, do they not?” We can be grateful that Lou Harrison’s last opera didn’t vanish in those depths after all.