Shontelle was raised in Christ Church and St James in Barbados
Shontelle used to be Rihanna's drill sergeant in the army cadets - but now she's her competition on the pop charts.
The 23-year-old singer grew up in Barbados, where she represented her country as a swimmer before finding success as a musician.
She signed a global record deal in 2006 and her first single, T-shirt, has just become a top 10 hit in the UK.
She talks about her background, her entourage, and making Rihanna do push-ups.
Good morning, Shontelle. Is this your first time in the UK?
Shontelle's next single, Stuck With Each Other, is a collaboration with Akon
Hi there! I've actually been here lots of times. I have family in London.
Do you remember your first trip on the underground?
Oh yeah. When I first came I thought it was gonna be similar to the subway in New York and I got down there and it was so much cleaner! And I was fascinated by the fact that it literally was a tube.
How did growing up in the Caribbean differ from London and New York?
Barbados was very laid back. Always sunny and shiny. We have 365 beaches - one for every day of the year - and it's a very small island, so everyone knows each other. Oh, and the food is amazing.
When did you write your first song?
I was kind of writing songs from as early as I can remember. I would rewrite Sesame Street songs and Christmas carols to make them more suitable to Barbados. So instead of Chestnuts Roasting On A Open Fire, I'd do Roast Fish On An Open Fire.
Did you perform them in school?
Oh yeah! I used to love performing on stage. Any opportunity I could find. A concert, a talent show, a pageant, you name it - I was on the stage.
So how did you get your big break? Don't tell me… it was that song about barbequing fish.
Nooo! The first big break I had was at home when I wrote a song called Roll It Gal, which Alison Hinds sang, and it became a smash.
After that, I got a call from a production company in New York and they asked to meet me. But we went to the studio and they put me on the spot, broke out a guitar and made me sing.
That sounds worse than American Idol
They didn't even ask me what I wanted to sing, they just started playing Killing Me Softly.
Rihanna, 20, was under Shontelle's command in the army cadets
Every interview I've read compares you to Rihanna - is that fair?
Um, I don't know if it's fair or unfair, but I recognise there's a curiosity around this situation. It's kind of a phenomenon having two girls from the same tiny little island making music that's being played around the world. People are fascinated by that.
Is it true you were her drill sergeant in the army cadets?
Yes, I was! We were both in cadets together - it wasn't compulsory or anything. But picture me and Rihanna in combat boots and fatigues crawling through mud and things like that.
You had to order her around?
That's what drill sergeants do. We boss cadets around, we make them do push-ups... especially when they show up on the parade square late.
Next year, at the Grammys, you have to creep up behind her, blow a whistle and scream a command at her…
Yeah! ! I'll be like: "Get down and push 10 right now!"
These days how do your entourages compare? Do you have 45 people with you, too?
Oh no, it takes a while to get to that stage. Some artists are kind of over the top - but most of the time, you need that many people. You know, it's all crew and assistants. And then you get lonely on the road, just hanging out with people you work with, so sometimes you'll bring along a couple of friends so you don't go insane.
But it takes a while before you can even afford an entourage. You've got to feed all those people, find somewhere for them to stay. It's not cheap.
You've just finished touring with New Kids On The Block. Are you even old enough to remember them first time round?
Yeah! I had cousins that were really into them. Obsessively, unhealthily into them. And they had all the fanzines and posters, pins, buttons, you name it. So I had no choice but to know about New Kids On The Block.
They must be seething with jealousy now.
Yeah, they are. I told them and they said: "We hate you."
The star's album was recorded in New York, Atlanta, LA and Barbados
What's the story behind your single, T-Shirt?
Every girl, every woman at some point in her life meets that guy that has such an effect on her that, if he's not around, she doesn't want to see her friends, or take time to get dressed and go out.
And all you want to do is sit at home with the guy's t-shirt on - because it smells like the guy, and you can put it on and cuddle up with it and pretend he's there.
Is the song about anyone in particular?
Not really. I knew that a lot of girls could relate to it.
When it came out in the US, I started getting women emailing me and saying: "Shontelle, I'm so happy you did that song." And their husband had just gone to Iraq, or their boyfriend was in college, or in hospital. There are so many different reasons why you would be separated from someone you're in love with.
And there were people who told me: "I wear my dad's shirt because I haven't seen him in so many years." I never thought it would touch so many people. And the song's even more special to me because of that.
You're quite unique, in that you're a pop star with an actual, real-life degree.
Yeah, up until the time I was putting my album together I was at the University of West Indies studying philosophy and law. I had my music, but you've got to have a plan B.
So, you're a straight-A student, you have a degree, you competed in sport for your country, you were an army cadet, you have a hit single. Is there anything you can't do?
I can't fly! But I might work on that.
Shontelle was talking to BBC News entertainment reporter Mark Savage. Her single, T-shirt, and album, Shontelligence, are out now on Universal records.