"Move it or lose it, that's what they say," Diana Ross said on stage Sunday in San Francisco's Stern Grove, after her second costume change and after announcing that she turned 81 years old this year.

It's been a big month for outdoor concerts in San Francisco, with Outside Lands (Doechii was the hands-down top highlight), the Grateful Dead's 60th anniversary shows by Dead & Company, country star Zach Bryan and Kings of Leon on Friday, the Pointer Sisters at Stern Grove last week, and this weekend's shows by Damian and Stephen Marley, and the great Diana Ross.

Ross capped off Stern Grove's annual fundraising weekend, called the Big Picnic, when more resereved tables get set up and table reservations go for thousands of dollars — with the revenue from table reservations going toward keeping the festival free for everyone else.

Dressed in her signature oversized feathery robes and sparkling gowns, Ross sang medleys of her decades-spanning catalogue of hits, including Supremes songs like "Baby Love" and "Stop in the Name of Love," and 1970s favorites like "Love Hangover." She also sang a new song, "Some Day," written by her eldest daughter Rhonda Ross Kendrick — who also came on stage and sang several songs mid-set, to give mom a rest and another chance for a costume change.

Ross closed her set with "Ain't No Mountain High Enough" and a cover of Gloria Gaynor's "I Will Survive." And after the audience thundered and cheered to bring her back out for an encore, Ross returned to do the song "Thank You" from her 2021 album of the same name.

The only snafu came when Ross had some sound issues with both her microphone and her monitors — and at one point a sound engineer seemed to hand her a dead mic, or one that wasn't turned on.

Ad libbing as the issue was dealt with, Ross said, "It's like these AI cars. We have all these cars going around with no drivers. I can't sing without these monitors [clipped to me] these days, and it ruins my dresses."

Ross was the final act in a season that saw 10,000 to 11,000 people head out to Sigmund Stern Grove each Sunday, with acts that included Sleater-Kinney, Channel Tres, Orville Peck, and Chromeo.

The Stern Grove lineups the past two years have been especially star-studded and quirky, with acts appealing to a range of demographics. Last year's season included The Commodores, Lucinda Williams, Chicano Batman, and Chaka Kahn, along with electro-pop acts DRAMA and Franc Moody.

"We’re really excited because we’re in a generational perspective where we want this to go on in perpetuity," said Stern Grove Board Chair Matthew Goldman, speaking to the Chronicle last year. "That requires us to continue to evolve our audience base while not alienating existing audience members. It’s hard to be something for everyone, but we can try."

Goldman and his twin brother and Vice-Chair Jason Goldman, are fifth-generation stewards of Stern Grove, with the reins having been handed down to them from father Doug Goldman in recent years.

The first concert by the San Francisco Symphony in Stern Grove was held in 1932, hosted by the Goldmans' great-great grandmother Rosalie Meyer Stern, who had purchased the 12-acre property — formerly a homestead and home to a suburban resort, the still-standing Trocadero Inn — and given it as a gift to the city, naming it for her late husband. The first summer of free concerts in the park was in 1938.

Packing 11,000 people into the meadows and on the wooded hillside overlooking the stage is a challenge in and of itself — and the bathroom lines can be intense. But the mood remained cheerful and orderly on Sunday as it has much of this 88th season.

And come spring, we'll be looking forward to the lineup announcement for the 89th season.