Los Angeles ? Bart Simpson is acting like himself, which is to say naughty. And he sounds like himself, with that familiar mischievous lilt.

But Bart’s voice is coming out of a petite blonde wearing a fluffy, bright-pink wrap. Dumpy Homer has morphed into a lanky fellow, and mom Marge’s towering blue hair is brown and tastefully cropped.

The event was a “table read,” when the cast of “The Simpsons” gathered with a roomful of writers, producers and guests, using their imaginations to conjure up the animated family with the distinctive mustard hue.

It was just one of the steps toward crafting an episode of the Fox series that begins its 16th season at 7 p.m. Sunday. The run is remarkable for any show — but especially for one like this.

Irreverent, witty and willing to take on anything from politics to religion to family values, “The Simpsons” has provided a rare bit of spice for the oatmeal-bland bowl of TV broadcasting.

The table read, held in an oversize trailer at the Twentieth Century Fox studio where the series is produced, itself is a symbol of the show’s enduring popularity. A decade ago, it finished the season as the 67th most-watched show; it was No. 69 last season with 10.7 million viewers and won its time period among the coveted 18-to-49 age group.

Actors, producers and writers sit at a massive conference table, along with invitation-only visitors.

“I’ll look around and go, ‘Hey, there’s Elvis Costello,”‘ said Al Jean, an executive producer who’s been with the series since it was spun off in December 1989 from Tracey Ullman’s Fox series.

Singer-songwriter Costello, who provided his voice for one episode, popped up at the table read for another.

It’s a treat for observers but serious work for the cast and producers. This is the first time a script has been performed after months of writing and revision.

The assembled performers include Yeardley Smith, the voice of Lisa; Dan Castellaneta, who received his third Emmy this year for voicing Homer and whose other characters include Krusty the clown and Grampa Simpson; Nancy Cartwright as Bart; Julie Kavner as Marge; and Harry Shearer, who does an array of voices including Ned Flanders and Mr. Burns.

They’re working on an episode that won’t air until next season, typical for a labor-intensive animated series. A roughly 21-minute episode takes about nine months to create, including the animation work done domestically and in South Korea.

In the script at hand (written by Danny Chun), Marge and Bart are engaged in unusual mother-son bonding, breezing through Springfield on a tandem bicycle and singing “Sweet Home Alabama.”

Marge: “I can’t remember our last outing together.”

Bart: “It was to see that court-appointed psychiatrist.”

Marge: “Oh yeah. He should never have let you near that letter opener.”

Series creator and executive produce Matt Groening follows the script carefully, jotting down notes for the writers. Among his suggestions: omit a giggle from baby Maggie Simpson in one scene, and beef up another in which Marge finds herself without a partner for her new bike built for two.

“He wanted more of a visual with Marge being lonely, so we put in a parody of ‘Midnight Cowboy’ where Marge and the bicycle are walking around Springfield to that harmonica music,” Jean said.

After all these years, Jean has developed his own script shorthand: a check mark for a joke that gets a laugh, an “X” for one that falls flat. “Something that’s sweet but doesn’t necessarily get a huge laugh will stay in,” Jean said.

After all these years “it’s a fairly well-oiled machine,” Smith said.