In the run-up to Glastonbury, Janet Jackson raised a few eyebrows when she tweeted a line-up poster that put her name above the headliners.
To be fair, the star is a headline act at home in the US, where she's one of the most successful female artists of all time.
Her star was never quite as big in the UK, though, despite having 17 top 10 hits to her name, which made this festival set something of a gamble.
Admirably, rather than play it safe, Janet delivered a whistle-stop tour of her career, playing a relentless, non-stop medley of 21 tracks in just 50 minutes.
At times, the pace was dizzying. One of her biggest hits, The Best Things In Life Are Free, was jettisoned after the first chorus; and minor tracks Throb and Come On Get Up got a fuller airing.
For die-hard fans, it was a dream setlist (and there were plenty of them singing their lungs out) but for a festival crowd unfamiliar with the corners of her back catalogue, some of the song choices were perplexing at best.
But the blessing of the attention-deficit setlist was that every time an album track started up, a pop banger was just around the corner - whether it was the punchy 1980s funk of What Have You Done For Me Lately, or the breezy pop melodies of Escapade and Miss You Much.
It was a physically-demanding performance, full of crisp, impressive dance moves - often directly lifted from videos Janet shot 30 years ago. But the 53-year-old easily fell in step with her troupe of eight dancers, despite wearing a heavy tail-coat in the 30C heat.
She paused only once, to dab the sweat off her face with a towel, which she then threw aggressively to the floor so she could get on with the next routine.
In fact, she seemed happiest when she was goofing off with the dancers, breaking into laughter when one blew her a kiss during Escapade, and tossing around her red tangle of curls as they vamped on some of The Jacksons' old routines.
Janet's vocals were sometimes too quiet in the mix, but she seemed to have worked out a way to sing - mostly - live while galloping around the stage; and the rip-roaring Black Cat proved she could belt it out when she needed to,
Never the most loquacious of stars, her stage banter was minimal, save for a few exhortations to sing along and, during Nasty, declaring: "I could learn to like this, Glastonbury".
Meeting the press backstage after the show, though, she said the view from the stage had been "amazing".
"So many people," she marvelled. "Everybody seems to really enjoy it every single year. I hear so much talk about it."
It's easy to overlook what a trailblazer Janet was in the 1980s and 1990s, emancipating herself from her overbearing father, Joe, and singing about female empowerment and sexuality long before Beyonce and Rihanna.
Meanwhile, her Rhythm Nation album was ripped from the headlines, with songs that tackled social injustice, racial prejudice, homelessness and illiteracy.
Two of those songs, State Of The World and The Knowledge, formed a centrepiece of Saturday's set, and sadly proved as relevant now as they were in 1989.
But it was the hits, not the deep cuts, that really connected. The lovestruck funk of Love Will Never Do (Without You) was a highlight, as was the military stomp of Rhythm Nation, which closed the set.
A technical delay at the start of her show meant the planned encore of Together Again had to be dropped.
In the final analysis, it might have been wiser to drop the jukebox approach and concentrate on 10 or 12 guaranteed bangers, but after what felt like a 50-minute tour of modern R&B history, you couldn't accuse Janet of slacking off.
She's done a lot for us lately.
- Trust A Try
- What Have You Done For Me Lately
- R&B Junkie
- The Best Things In Life Are Free
- All For You
- Come On Get Up
- Rock With U
- That's The Way Love Goes
- Made For Now
- State Of The World
- The Knowledge
- Miss You Much
- Love Will Never Do (Without You)
- Black Cat
- Rhythm Nation