"30 years ago today," acknowledged Prince with a sly smile as the artist who's previously downplayed the occasion's significance segued from "Let's Go Crazy" into "Take Me with U" on Saturday night at Paisley Park.

Just a week after making my first-ever visit to Paisley Park, I was again invited out to Chanhassen last night—along with 176,000 other people who follow @3RDEYEGIRL on Twitter. The occasion had been billed as a "listening party" with Prince's band 3RDEYEGIRL, who are preparing to release their album Plectrum Electrum. That advertising was accurate insofar as there was indeed a lot of listening, and there was indeed a hell of a party—which, as the artist himself noted, just happened to take place as the calendar was turning over to the 30th anniversary of the release of the film Purple Rain.

(Hear a new audio documentary about the film and its legacy, by Andrea Swensson and Tom Weber; I also wrote an essay about Prince's career and its significance.)

My girlfriend Dana and I arrived at Prince's studio and performance space about a half-hour after the doors opened at 9:30 p.m. A few hundred people who had paid $25 each for admission and a piece of merch (a poster) filled the smaller of Paisley Park's two performance rooms. The house band were already playing a hot set of jazzy funk, as the room's screens displayed a montage of nature footage.

The set reached its climax after a few more songs; as the band wrapped up their last number, a giant door behind them opened to reveal a bright purple glow from the large performance room, where a stage was set up with 3RDEYEGIRL's instruments and Prince's trademark love-symbol mic stand. As we walked in, Prince said hello to us via 3RDEYEGIRL's recorded version of "The Unexpected," a Prince-penned track that also appears on LiV Warfield's new album.

After only a few minutes, the four members of 3RDEYEGIRL—guitarist Donna Grantis, drummer Hannah Ford, bassist Ida Nielsen, and Prince—jumped on stage and wasted no time whipping into an instrumental guitar jam. Nielsen, Ford, and Grantis were dressed in glamorous stage costumes, and Prince was clad in an outfit that seemed to defy classification when Dana and I tried to describe it on the car ride home. ("Would you call it a pantsuit?" "Well, there were pants, but there was also a vest." "I'd call that more of a scarf. And there was that knit-like hat...") As the 300 or 400 fans spread out along the arena-sized stage, Dana and I were easily able to stand less than 20 feet from Prince.

Having squalled up a storm, Prince stepped to the mic and spoke the immortal words, "Dearly beloved, we are gathered here today to get through this thing called life." That was prelude to a version of "Let's Go Crazy" that traded the original's danceable beat for a swampy, suggestive hard-rock crunch that would make it a good fit for Plectrum Electrum. That was followed by an exuberant trio of "Take Me with U," "Raspberry Beret," and "U Got the Look."

"It's karaoke night at Paisley Park," said Prince as he invited the audience to field most of the vocals on "Raspberry Beret." It was similar for "U Got the Look," and then our job got a little easier: we just had to yell "Paisley Park" in time as the band jammed, with Marcus Anderson contributing sax solos and Cassandra O'Neal on organ. Having moved from guitar to keys, Prince sang a light and lovely rendition of "The Ballad of Dorothy Parker" from Sign o' the Times.

Prince then handed the keyboard over to Kandace Springs, a Nashville singer-songwriter whom Prince had invited to perform in Minneapolis, he said, "because y'all are respectful. You love music...and I think you love me." Roars of agreement turned to a hush as Springs performed a tender cover of Ewan MacColl's "The First Time Ever I Saw Your Face," Springs's ethereal vocals floating over a wash of layered chords from the keys.

Appearing back onstage, Prince and 3RDEYEGIRL launched into a gospel-flavored "Nothing Compares 2 U," Prince again inviting the audience to sing along but also letting his own vocals rise to a full-throated plea. He then told us that we should go back into the smaller space for a solo set by Springs..."but before you go, there's just one thing I want to say!" As the opening riff to "Kiss" rang out, Prince grinned. "That's walking music!" he said, pointing towards the other room. "Why aren't you walking?"

Of course, he knew we weren't about to go anywhere until he'd finished a playful performance of the chart-topping hit, appearing—as he had throughout the set—completely relaxed and happy to be playing some of his most famous songs with his new band of virtuoso players. After that, though, it really was time to move into the other room, where Springs played a set that showcased her classic soul-blues sound and formidable pipes.

How relaxed was the vibe? So relaxed that Prince just strolled right past Dana and me, not once but twice, as we watched Springs's set. Moving to the front of the crowd for her last few songs, our host even joined in on congas for the band's final jam.

When Springs and her band wrapped up, we moved back into the big room for...well, for more listening, to a carefully curated DJ mix, during part of which Prince appeared behind the soundboard. Standards like Chic's "Le Freak" were mixed in with new and so-new-it-hasn't-even-been-released Prince material, including the meme-inspired "This Could Be Us." When it became clear that 3RDEYEGIRL weren't going to immediately retake the stage, Dana and I walked around the space and said quick hellos to DJ Michael Holtz, who mentioned that Prince had found Springs via her cover of "The Beautiful Ones"; and to Grantis, who told me the band have lately been at Paisley Park six days a week writing, rehearsing, and recording.

As the hour grew later, several dozen people took the dance floor—we happily joined them for the Wobble, which Holtz reprised from last weekend—while others lounged on sofas, stood conversing, or queued up for merch and bottled water. A shrinking cluster of hopefuls clung to the front of the stage, but the final verdict as to whether the band would return was delivered when, after we heard "The Breakdown," the house lights came up around 2:30 a.m.

"That was like a concert in reverse," said Minneapolis singer-songwriter Mark Mallman as we walked back to our cars. It had certainly been an unforgettable evening-slash-morning, and Mallman had put a pithy point on it earlier while we'd stood looking up at the golden glyph on Prince's mic stand. "I just like," Mark said, "to support local music."