By Kenneth Herman

SAN DIEGO — In this time of rampant crossover trafficking in the musical world, someone should recognize this new category and give an award for the most daring artistic about-face.

Leading contenders would include Paul McCartney, the ex-Beatle whose autobiographical oratorio recently debuted in the Liverpool cathedral; Andrew Lloyd Webber, the megahit stage musical tunesmith who fabricated a Requiem, and all those Metropolitan Opera baritones who are falling over each another attempting to record every musical comedy penned since Rodgers met Hammerstein.

At least "The Forest," rock star David Byrne's opus for orchestra and nine vocalists, avoids the hubris of his British counterparts. With Byrne and an octet of singers from Los Angeles, the San Diego Symphony gave "The Forest" its local debut Sunday night at Copley Symphony Hall.

Guest conductor Jonathan Sheffer, whose grandiose demeanor conjured the old Hollywood stereotype of the flailing, self-absorbed podium wizard, led the performance, the third time "The Forest" has been mounted in the United States. Sheffer will also conduct the work in Seattle and Minneapolis.

As an orchestral composer, Byrne is not likely to nose out the traditional three B's: Beethoven, Bach and Brahms. The style of Byrne's modest hourlong tone poem falls somewhere between contemporary symphonic minimalism and an orchestrated long-playing rock song. Except for a few star turn vocal solos by the composer, "The Forest" noodled along in a pleasant modal vein, predictably alternating tranquil ruminations with rhythmically inflected dance sections.

Byrne's solo vocal flights were as unassuming as the work itself. A few forays in his trademark falsetto, some pseudo-primitive incantations, and a dash of decorous howling summed up his contribution to the tonal texture. The vocal ensemble's pure, open intervals and African-inspired rhythmic chanting proved more engaging.

Constructed in 10 compact, thematically self-contained movements, "The Forest" did not aspire to any grand architectural complexity. Such defects, however, never bothered Richard Strauss or Frederick Delius, to cite a pair of tone poem gurus from another era. The plush orchestration of "The Forest," the work of Jimmie Haskell, whipped up lush string sounds relieved by militant brass solos.

The orchestra, subtly miked to balance the heavily miked vocalists, played well for the 2,135 in attendance, 100 short of a full house.

Notable solo contributions came from the first desk cellists in the beginning of Part 6 and from concertmaster Igor Gruppman, whose animated cantillation in the eighth movement displayed the wry humor of a Klezmer fiddler. Guest musician Brian DeWan supplied a quaint zither solo in Part 4.

In his ample program notes, Byrne credited ancient Sumerian mythology as the source and theme of his orchestral opus. Since only one movement uses a cognitive text--it was something about two men drinking in a bar--any allegorical implications of "The Forest" will rely entirely on intuition and suggestion.

Sheffer opened the concert with a perfunctory trio of overtures, pumped up for maximum sonic effect and a minimum of interpretive insight. He chose Wagner's Prelude from Act III of "Lohengrin" and the Prelude to "Die Meistersinger," as well as the Overture to Mozart's "The Abduction from the Seraglio."