Rihanna, The Forum, London

Three songs into her set, Rihanna hollers with shameless gusto as she brandishes a mobile phone: “Everybody say HTC! Say Budweiser! River Island!” So this is what pop stars have become a vehicle for: blatant advertising.

The plug for her own music comes later – today the 24-year-old singer has released her new album Unapologetic. It’s her seventh album, released in just seven years, and her current promotional tour is a whirlwind even by Rihanna’s standards – seven gigs in seven countries over seven nights via the 777 jet taken over by an entourage of attendees, journalists and fans.

Tonight is the sixth night of concerts for competition winners, at the humble 2000-capacity Forum, a tiny venue when you consider that the several million-album selling Barbados-born star is accustomed to arenas. Bar the centre of the stage, which is left clear for the model-esque Rihanna to strut and wind provocatively, the musicians look cramped on this undersized stage - two dancers, a guitarist and drummer to the left, guitarist and synths to the right.

Despite the globe-travelling, the star is radiant in a leopard-print sports bra, slinky white tracksuit, towering red stilettos and plenty of gold bling – and she oozes laid-back charisma and genuine smiles of enjoyment in a performance that shows she was born for the stage. With much singing pre-recorded on backing tracks, she doesn’t even attempt to hide this fact, as on 'Only Girl(In the Wolrd)', but when she does sing, it’s with that unfailingly smooth, level, and deeply satisfying, rich tone.

The only time that coolness is momentarily discarded is in 'Where Have You Been', when the clockwork set, in which pumping track leads to the next, falls out of sync. “Why is the track off with the band?” the singer demands, revealing her feisty side, ordering her band to restart the song.

There’s a smattering of new songs, including the stand-out single 'Diamonds', but it’s a greatest hits set for the fans, including S&M and the reggae-tinged 'Man Down'. A couple of acoustic ballads make a welcome change of pace from the predominantly heavy sound of techno, rock andand hip-hop, and the set builds towards its second half. 'Umbrella', the hit which shot her into the pop stratosphere, is the euphoric finale, transforming the venue into a heaving club – no mean feat on a Monday night - as jets of smoke and silver confetti erupt from the stage.

And in a flash, Rihanna is transformed with a black outfit and baseball cap, ready for her next mission.