What do Paris Hilton and Nicole Richie know about opera?

It was a sight people certainly didn’t expect to see: Paris Hilton and Nicole Richie sitting down with Thomas Adès, one of the greatest living composers, to learn about opera.

Adès is a longtime fan and admirer of them, he tells the camera in “Paris & Nicole: The Encore,” a sequel to “The Simple Life” now streaming on Peacock. The women come to him with a tune, which he echoes at the piano.

They ask him: Can he write their opera? He tells them, with evasive politeness, that he’s not sure he’s the right person for the job. Then they ask him how long it takes to write an opera. One to five years, he says.

They have less than a month.

It’s an enlightening moment, one of many it turns out, in “Paris & Nicole,” a three-episode lark about Hilton and Richie reuniting to write an opera based on their decades of friendship.

This art form, they learn with jaws dropped, isn’t easy. In fact, as the series shows, it’s unbelievably hard.

Still, they are determined. Hilton and Richie, visibly mature and mostly shaking their Y2K-era ditsy personas, set out to compose an entire opera using just one word: sanasa.

As fans of “The Simple Life” may remember, Hilton and Richie often have sung “sanasa, sanasa” at each other. They go into their new series wanting to write what they call “The Sanasopera!,” but, in the spirit of “The Simple Life,” not knowing how.

At least the libretto of one word is already done. They just have to spin it into a spectacle that, they say, will be Studio 54 meets “Willy Wonka and the Chocolate Factory” meets “The Wizard of Oz” and “The Phantom of the Opera.”

Why opera? Hilton says, “It’s so random, it’s perfect.” Richie adds, “It’s also very us to dive into a world we know nothing about.”

But a premise is just a start, and that’s where the series becomes a subtle bit of advocacy for opera. Hilton and Richie learn that this glorious, grand thing they want to make requires a lot of money, time and talent. The performance is just a surface-level display of an enormous operation.

They play dumb here and there; Hilton, who has been spotted at Lincoln Center, says she doesn’t know what “Madama Butterfly” or “La Traviata” are. Asked what style their opera will be, she responds: “Hot. Iconic.”

As they reach out for help, though, an understanding of opera emerges. The impresario Beth Morrison informs them that they will need about $1.5 million to pull off an opera of their ambition.

Adès also suggests they visit a voice teacher. They do, and learn how operatic singing works.

Hilton and Richie’s network, admittedly, is better than that of most composers. For marketing, they ambush “LA’s fast-food and opera-loving crowd” at Sonic, join Kesha in taking over a sightseeing bus tour and invite everyone to see their show. Facing rejection at Sonic, Richie responds, “OK, so just the slushie.”

It’s all undeniably, sweet, though. And the point was never to create a masterpiece. Like “The Simple Life,” this series is about the journey, one in which they, and we in turn, hopefully learn something about this “iconic” thing called opera.