Backyard boogie.

Katharine McPhee serenaded Spencer Pratt during a fundraiser the singer and her husband, David Foster, threw for the reality star’s Los Angeles mayoral run.

The couple threw a lavish fundraiser for the mayoral candidate in the backyard of their Brentwood Park home in Los Angeles over the weekend.

Per a video shared on Instagram by news personality Alicia Summers, Foster, 76, played the keyboard while his wife, McPhee, used new lyrics for Tina Turner’s hit “The Best,” singing that Pratt is “better than [LA Mayor] Karen Bass and [LA Councilmember] Nithya Raman.”

At one point, the former “American Idol” runner-up forgot Raman’s first name, referring to her incorrectly as “Cynthia.”

When McPhee, 42, mentioned the mistake, Pratt, also 42, shrugged his shoulders in uncertainty.

“You know the tide is turning in California when @DavidFoster and @katharinefoster open their home and write a song for @SpencerPratt 👏 La La Land is ready for a plot twist 🗳️,” Summer captioned her Instagram post Tuesday.

The guest list for the swanky backyard soirée included film producer Brian Grazer.

Both Bass and Raman are the “Hills” star’s two leading opponents in the race for mayor.

The former reality star decided to dive into politics after losing his home in the devastating 2025 Palisades fires.

In January, Pratt launched his campaign, which focuses on cracking down on crime, addressing the homelessness crisis and criticizing the city leadership’s wildfire response.

Several stars have shown support for Pratt’s political future, including Los Angeles Lakers minority owner Jeanie Buss, who donated the maximum $1,800 to the former MTV star’s campaign. 

Pratt also receives support from “Malibu’s Most Wanted” actor Jamie Kennedy, Meghan McCain and reality stars Jonathan Cheban, Jax Taylor and Kristin Cavallari.

The new LA mayor will be decided on election day on Nov. 3.