Rhianna, Jazz Cafe, London<br></br>Roddy Frame, Borderline, London

So, what's your Single of the Year so far? While you're thinking of an answer to that one, I can tell you mine like a shot: "Oh Baby", by Rhianna.

From the moment it crackled over the charity shop's speakers, helium-high and sucrose-sweet, unexpected as a thunderbolt from a blue sky, it took up residence in my head and refused to leave. A dreamy shot of soul-pop perfection, reminiscent of Saint Etienne or PM Dawn and built around an obscure lounge-pop loop (a sample, it transpired, from The Tony Valor Sounds Orchestra's "Amore Santos"), it has spent the last three months spinning around my skull so relentlessly that, without even needing to actually play the damn thing, it's been the soundtrack to my summer. Its provenance was a complete mystery to me (who was this Rhianna, and where did she come from? Britain? America? Europe? Australia?), and I quite liked it that way.

Rhianna Kenny, it turns out, is a 19-year-old from Leeds with a Cuban mum and an English dad, who went to drama school and served her apprenticeship with her big brother Leigh in LSK, a briefly-touted acoustic soul act. Tonight's show is her first "proper" solo gig, and after a summer spent on the roadshow PA circuit, this is clearly some relief ("It's nice to be performing in front of people over the age of 16").

In person, Rhianna's every bit as sweet as her debut single. With her 'fro and freckles, she looks like a girl-next-door version of Foxy Cleopatra, and may yet reclaim the Leeds accent from Scary Spice hell. At this stage, though, her coolness remains a hostage to fortune, and there are danger signs that "Oh Baby" may have been an isolated flash of inspiration. Not that the follow-up, "Word Love", is a disappointment: the offspring of Chaka Khan's "I Feel For You" and The Jacksons' "Shake Your Body Down To The Ground", it's plenty funky. The problem is an obsession with keepin'-it-real (perhaps a legacy of her acid jazz background) which, given that her breakthrough song was such a glorious confection, is slightly sad.

"Isn't it nice to see a young lady singing without a backing tape?" she says with undisguised self-satisfaction. Which is all very well, but it's a bit rich to be playing the Keep Music Live card when, two songs earlier she had been duetting with her own pre-recorded backing vocals.

In interviews, Rhianna lists Stevie Wonder among her influences; tonight, she covers his "I Love Every Little Thing About You", but has to abandon an audience singalong when it becomes clear that they've never heard of it.

Her choice of covers is, at least, unusual. She does "The Moon Is Blue", an Eighties non-hit by Colourbox, but inexplicably turns it into a stereotypical Brand New Heavies-ish workout, stripping away all the torch song intensity of the original (next time you're on your favourite Napster/ Audiogalaxy clone, track it down and prepare to be knocked sideways).

Her original material also tends towards jazz-funk orthodoxy. She claims one song was written by her brother and finished off by herself, although Barry White might argue (it's a clone of his "Never Never Gonna Give You Up"). Either way, although she joshingly asks the people in the posh seats upstairs how the top of her head's looking, this music is meant for bourgeois diners. But still, as she proudly reminds us, we've been watching a "real band" featuring "real people", and to Rhianna Kenny, that's what matters most.

Summer in the city where the air is still, and several hundred men of a certain age (oh, women too, but mostly men) have turned the Borderline into a subterranean sauna. The organisers of this summer's The Song's The Thing festival may, like Rhianna Kenny, hold some fairly noxious views about what constitutes a "real song" (they would, you suspect, think that "Can't Get You Out of My Head" isn't one, but that abomination by Vanessa Carlton is), but you can hardly blame Roddy Frame for that.

The man who, let's be honest, was Aztec Camera is the reason that the Borderline's packed so sardine-tight (and has been for the previous three Tuesdays), and Frame's faithful know their stuff: when they chant "High! Land! Hard! Rain!", he jokes that the people in the Tex-Mex restaurant upstairs will think there's a Nazi rally going on.

There was a whole lotta jangly, Byrdsian indie pop coming out of Scotland in the early 1980s, but Aztec Camera's was a cut above: partly through Roddy's fondness for fast-fingered, flamenco-influenced string-picking, but mainly through his innate ability to convey the moods and minutiae of what it feels like to be a teenager head-over-heels in love. He had, of course, an unfair advantage: when Frame first emerged from Westwood, East Kilbride in a tassled suede jacket with a sunburst guitar tucked under his arm, he was only sixteen.

Roddy's eyes have the same steely blue glint as ever, although these days he's bearing an increasing resemblance to Edward Woodward in The Wicker Man. That voice, though, still resonates with romance. This acoustic show revisits his entire career, from ancient Postcard Records singles like "Mattress of Wire" to selections from his new solo album Surf, but only includes two songs ("Somewhere in My Heart" and "Oblivious") you could call "hits". I'd have killed for "Walk Out to Winter", but you can't have it all.

He's clearly having fun, although you wonder why Roddy, a shy man, and never a prolific performer, feels the need to do this. Then again, if, "While you were gone I reached another town / They couldn't help me but they showed me round" is a hell of a line to write at 16, "And if the prophets knocked my door with all that heaven held in store / I'd probably ask to see a sample" ain't too shabby for a 38-year-old either.

s.price@independent.co.uk

Rhianna plays V2002 at Hylands Park, Chelmsford (020 7287 0932), today, and supports Beverley Knight on tour later in the year