Live Review: Jessie J Professor Green Festival Hall

Britain's urban scene is exploding and two of its most hyped newcomers, Jessie J and MC Professor Green, are sharing tonight's bill at Festival Hall. There's much speculation about whether Jessie J will appear after she withdrew from previous Australian shows, jetlag (and fatigue) affecting her voice. But the plucky Essex girl ain't giving up, to the relief of the largely female (and teenage) audience here to see her.

First on stage is Professor Green. The rapper may be street 'n all, but he has a strong female following, partly because of his association with Lily Allen. Green might headline in his own right with a band this tight (he has two backing vocalists – one male, one female). The rapper rollicks through his early singles: the INXS-sampling I Need You Tonight, SOS Band-jacking Just Be Good To Green and stadium-hop Monster. Yet he's also showcasing his second album At Your Inconvenience and, in fact, the ultra cool drum'n'bass Trouble rocks. Green's finale is, of course, Read All About It, his biggest song. It seems slower live, but hits the spot. The crowd sings along, always a good sign.

Ruby Rose, obscured on the side of the stage, DJs between acts. It's back-to-back trancey urban pop fodder. However, the media personality fulfils her brief as hypewoman (though possibly not with that shout-out to “mum”). Right on time, the diminutive Jessie J, in a revealing and floaty red gown complete with suspenders, rips into the victorious Who's Laughing Now. Jessie has a voice to rival that of Beyoncé, if not Adele, but could drop the cutesy affections of Rainbow. She performs a calypso-tinged Stand Up, segueing nicely into Bob Marley's One Love.

It's been claimed that Jessie J is better live than on record. That's true. Still, her band's arrangements are fussy at points. Ballads such as the acoustic (and Lauryn Hill-ish) LOVE allow her room to move as a vocalist. Later, she pulls off some expert jazz scatting. Nevertheless, the show's pinnacle is the '70s throwback Abracadabra – even funkier live as Jessie channels Thelma Houston. And the Brit is a chatty, winsome performer, explaining (and apologising for) her voice woes.

The encore necessitates a costume change, this time Jessie's curious attire tying in with Do It Like A Dude. For Price Tag, she brings up a wannabe singer from the audience – who's actually first-rate. But vocal strain or no, Ms J really is in a league of her own.