It’s pretty easy to pigeonhole all but one of Pop’s Female Superstars these days. Beyoncé is the Obama-approved Queen of Child-Friendly Sexiness. Lady Gaga is the High Fashion Princess of Positivity. Madonna is the Wicked Witch of the West. Rihanna, on the other hand, just isn’t that straightforward.

Even after her Diamonds World Tour made its twelfth stop in Vancouver’s Rogers Arena last night, we’re still left with more questions than answers.

Admittedly, the press for the tour so far hasn’t been the best, citing Rihanna’s tendency for erratic behaviour, highlighted by a newfound adversity to punctuality and a laissez-faire attitude towards singing live. Vancouver escaped lightly on the first count, the house lights dimming a mere 55 minutes after the advertised kick off time. The crowd didn’t seem to mind much, entertaining itself after a garbled set by support act A$AP Rocky by dancing along to a high volume intermission DJ, peaking with a rousing reception and reaction to “The Harlem Shake.”

In Pictures: Rihanna shines bright like a diamond in Vancouver

It didn’t take too long after Rihanna’s arrival before a buzz went around the arena about what vocals were and weren’t coming from her mouth. The excellent “Phresh Out The Runway,” “Birthday Cake” and “Pour It Up” were all punctuated by moments when Rihanna brought the microphone away from her face or simply stopped singing entirely, even when the vocals filling Rogers Arena were still going strong. With two backing singers nearly out of sight, and a few of Rihanna’s own pre-recorded vocal tracks running simultaneously, the effect was actually more jarring than mere gaps in simple lip synching.

Having dropped the pretence that every note was coming directly from her, Rihanna seemed to be enjoying herself, languidly gyrating everything below her waist while her top half seemed almost half asleep. Her heavy eyelids were so noticeable that she actually emerged for “You Da One” after her first costume change wearing a pair of sunglasses.

But here’s the thing. Even though an arena concert with a possibly-not-singing, potentially high performer sounds like a recipe for disaster, Rihanna is no mere pop star. Over the course of three reggae-tinged songs, “Man Down,” “No Love Allowed” and “Rude Boy,” all performed without a shred of organised choreography, Rihanna demonstrated the difference between singers and superstars. Every move was magnetic, every word resonant. Radiating charisma and sex appeal, from that point onwards it was impossible to take your eyes off her.

The dancers and the band all returned in shiny outfits as the show went up a gear with the r’n’b pop masterpieces “Jump” and “Umbrella,” both accompanied by hefty doses of pyro. When Rihanna instructed the crowd to “Put your diamonds up!” for “Rockstar 101” that’s exactly what they did. The ballad chunk of the show, featuring a version of “What Now?” dedicated to anyone “confused by love” was rapturously received. Swapping the red ballgown for a sparkly raver’s jacket and shorts was the cue for the big floor-filling finish, beginning with a version of “We Found Love” that saw Rihanna enter the crowd for countless high and low fives and a pair of genuine hugs, and ending with banging renditions of “S&M” and “Don’t Stop the Music.”

As a musician, Rihanna’s reluctance to rely on live vocals asks questions about whether she’s quite the singer she’s reputed to be. But as an artist, last night’s concert – with its relaxed approach to choreography, a relatively limited stage set, and multiple moments of personal vulnerability despite hit after hit performed with a near-pathological degree of swagger – suggested that she could go any creative direction she chooses.

And although she remains the hardest pop diva to define, on last night’s evidence it’s the wild ones, in Vancouver at least, that we really fall in love with.