A mixed bag; so what?

Opera always has a party side. So, what’d they wear? How did they sound? How did they act? And what about the decor? But when a company throws a bash, as Los Angeles Opera did at the Dorothy Chandler Pavilion on Tuesday night with its “Placido Domingo and Friends” gala, what everyone wants to know is: Who came?

Happily, Domingo attracts an operatic A-list. This year he was joined by the stellar likes of Renee Fleming and Denyce Graves, as well as the hot, young Peruvian tenor, Juan Diego Florez. Sting filled in for an indisposed Audra McDonald. Hollywood celebrities -- actors Sidney Poitier, Salma Hayek, Rebecca Romijn-Stamos, Kelley Hu, Zooey Deschanel, and Hugh Jackman; the directors William Friedkin and Garry Marshall -- introduced the singers. It began when a voice over the loudspeakers announced “Five-time Academy Award-winning composer, John Williams.”

The curtains parted, and he walked across the stage and down into the pit to conduct.

A music critic is a little out of place at such an event. The program is a relentless showcase of star power applied to hit arias or popular songs. There is very little rehearsal time and typically an over-eagerness to entertain. The goal is fund-raising, and any operatic consciousness-raising that might come along on the side is a bonus. If a good time is had and money is made, the evening is a great success.

The Chandler was well filled, and the program, which lasted more than two hours without an intermission, seemed to do its job. It was amusing to hear Poitier, at his most oracular, introduce Domingo, in his appearance with Fleming for the love duet from Verdi’s “Otello,” by booming out, “The Moor is back!”

The down side of these events is that reliance on star power, without the full trappings of opera, is often disappointing. Domingo and Fleming have been riveting in “Otello” at the Metropolitan Opera. But Domingo has retired the role, and here -- with neither singer warmed up, with Williams doing little to create dramatic atmosphere from the pit and the singers without theatrical direction -- the performance had little impact.

Still, Fleming and Domingo came into their own in solo numbers. The soprano may have brought an almost forced beauty to the “Hymn to the Moon” from Dvorak’s “Rusalka,” but she made “I Want Magic,” from Andre Previn’s “A Streetcar Named Desire,” especially moving.

Domingo relaxed comfortably into a zarzuela number and was irresistibly expansive in “Granada.” In between, with nothing else to do, he relieved Williams at the podium by conducting the middle third of the program.

I’d like to hear Florez in a hall half the size of the Chandler and with more bloom. In two Donizetti arias, he certainly indicated what all the fuss is about. But his highly appealing lyricism begs for intimacy, and the Chandler’s acoustics seemed to tighten him.

Graves was uncharacteristically gravelly in her selection from Cilea’s “Adriana Lecouvreur,” gravelly and mannered singing Johnny Mercer’s “Blues in the Night.” Vladimir Chernov was not in the best voice either, though he tried to make up for that with some timid “Saturday Night Fever” moves as Rossini’s Figaro.

Curiously, the two least-known singers were the most impressive. Maria Guleghina, in “Vissi d’arte” from “Tosca” and “Casta diva” from “Norma” is overly enamored with the effect of a swell from the softest pianissimo to a house-filling forte, but she keeps your attention glued. Andrea Rost, disappointing in last season’s “Magic Flute,” sang “Caro nome” from “Rigoletto” with such flare and wonderful coloratura that she now makes one eager to hear her later this month in “Don Giovanni.”

On the pop side, Sting was Sting, warmly singing “Fragile.” Kristin Chenoweth was the only theatrical singer, and although her shtick in “Glitter and Be Gay” from “Candide” verged on the hokey, she was terrific anyway.

Something remarkable happened at the end, when the company appeared for what sounded like a barely rehearsed run-through of “You’ll Never Walk Alone.” Williams’ tempo was slow, the L.A. Opera Orchestra mushy sounding, when Graves came in with a deep, spiritual tone, it was as though the clouds were lifting. That proved a fleeting moment. Graves’ tone was not picked up by the other singers and eventually the whole thing fell apart, as the scrappy L.A. Opera Chorus joined in, producing something close to a microtonal choir. But by then no one really cared, and everyone looked like they were having fun.