RIHANNA is the hardest working woman in music right now.

She’s had a relentless run of hits - 17 Top 10 singles in Australia since 2005 and four No.1s in the past year alone.

Where most pop artists fear overexposure, Rihanna has not taken a break since her first hit, producing an album a year, making countless cameos on other people’s singles and touring regularly.

Last night’s sell out show at Rod Laver Arena coincides with Rihanna having the most popular song in the country right now, the controversial S&M, where she sings "sticks and stones may break my bones but chains and whips excite me."

The Barbadian's barely-there outfit for S&M, a skin-tight PVC dress with a see-through G-string, highlighted one of the show’s most exploited props - her backside. Two dancers literally wave whips and chains wearing flesh colored bodystockings and little else.

And in case you missed the metaphor, Rihanna straddled a pink cannon for Hard. There was also some girl-on-girl action for Ti Amo and plenty of stripper-esque dance moves.

Yes, a Rihanna show is not for prudes. Some would say with all the racy costumes, crotch grabbing and sexually-charged lyrics about male, er, performance and girth, it’s not a show for young kids either, but that’s a parental choice - there were plenty of teens and pre-teens in the house.

Watching kids under 10 (and there were plenty of them) sing along to lyrics like "sex in the air, I love the smell of it" or "meet me in the boudoir, make my body say aaah aaah aaah" or "come here rude boy can you get it up" was kind of creepy.

Before S&M, Rihanna told the crowd, "I want you to sing every word." However, often she didn't return the favour.

Her Australian shows have started an online debate about how much of the concerts Rihanna actually sings.

While there’s plenty of points where she’s obviously singing live - breathless and letting the over-worked backing singers and rabid crowd fill in the gaps - some moments sound suspiciously like she’s singing over her own pre-recorded vocals – a trick employed in many pop concerts.
At least Rihanna doesn’t phone-in her live shows, genuinely interacting with her fans, and she can already do a greatest hits set with killer singles Don’t Stop the Music, Only Girl in the World, SOS, What’s My Name, Rude Boy, Shut Up and Drive, Disturbia and Umbrella mixing with ballads Love the Way You Lie, Take a Bow and Unfaithful.

Strangely, Australia got a one-off reprise of last year’s Last Girl on Earth tour, which Rihanna stopped touring last August.

Her Loud tour starts overseas in June. At times the show felt a little rusty and focussed on previous album Rated R, although a handful of Loud singles had been shoehorned into the old setlist.

Rihanna’s final Melbourne show is a Rod Laver Arena tonight.