So what about the music? The hip alt-rock crooner and serial collaborator (Anne Sofie von Otter, the Brodsky Quartet, the Academy of St. Martin in the Fields, to list just a few well-known classical names) should have stuck to writing biting love songs rather than classicial music. Il Sogno has been compared to the work of composers like Copland, but I don't see the comparison. The bouncing orchestration often sounded like "On Broadway" or even the soundtrack to Shaft. The piece had little in the way of a memorable melody or theme, and showed almost no ability to write meaningfully for competing lines.

Its mishmash of jazz, big band, and movie soundtrack unison string swells were fine for what they were, but there was little else on offer besides drum- and sax-backed Broadway vamping while the scenes changed. The music telegraphed its intent clumsily ("now the music sounds eerie" …"now we're getting funky" … "now people are dancing" … "now the storm clouds are gathering" …"now we're marching like Sousa" … "look at the magical fairies!"). And Costello seems to have thrown in every instrument he could find (the cimbalom, i.e., hammered dulcimer; the alto sax; the celesta).

Even the San Francisco Symphony, battle-hardened after pop concert jams with the likes of Metallica, looked profoundly bored during the piece, as if to say, "I didn't pay thousands of dollars to Juilliard to be Elvis Costello's toy orchestra." The piece, a suite of highlights from the full one-hour version, clocked in at barely a half-hour, after ending half-heartedly in a nonending that had me wondering when the next half was going to begin. The line in the program from Midsummer Night's Dream suddenly seemed prescient: "And this weak and idle theme / No more yielding but a dream."

But no matter, it was time to grab a drink at the bar after the warmup band and get ready for the real show. For the second half, Costello came back on stage dressed in a natty tux and settled into an agreeable collection of new numbers mixed in with enough greatest hits ("Alison," "Veronica," "Watching the Detectives") to keep the fans' toes tapping and the Symphony at times in obvious delight. Throughout, he was sometimes backed by the orchestra in swooping pops-style nerdiness, sometimes "unplugged" with an acoustic guitar, sometimes backed only by the psychically attuned pianist Steve Nieve, who tossed off lines of stunning delicacy and grace between Costello's aching lyrics.

Listening carefully to Costello sing pop songs in a concert hall setting, it finally occurred to me what makes this singer's vocal technique unique. He attacks every note with his trademark third-interval slide up from a note below, barely in tune even when he reaches his intended note, and slowly wobbles through it all with a vibrato you could drive a truck through. He pairs that with crisp lyrics as literate as the hippest fiction, another critical ingredient of his success. It all somehow works amazingly well. (Both ingredients were missing in "She Handed Me a Mirror," a song that's part of a piece he premiered last year in Copenhagen for a Royal Danish Opera production about the life of Hans Christian Andersen.)

Costello, ever the dabbler, should stick with what he knows best and put the classical music writing back on the shelf for a while. Still, there's plenty of potential for a pops-classical career: When he played "The Birds Will Still be Singing," written for The Juliet Letters in a collaboration with the Brodsky Quartet, the orchestration suddenly made sense, springing to life with aching string lines paired with his balladlike lyrics about banishing all despair and extinguishing sorrow. Then when he put away the mike in his final encore and attempted to fill the hall with the fullness of his strained tenor range, it was if the pop singer was playing at being an opera singer. He had the delighted audience singing along, then on its feet, scooping up these somewhat tired musical moments out of the palm of his hand, always with that trademark sly, shrugging smile and through-the-square-glasses wink.