My parents are... very supportive. I remember asking for piano lessons when I was six, and my mum being like 'OK, cool, but if I'm paying for them you've got to practise'. They let me decide what I wanted to do but didn't let me take it for granted. They're both into music – my dad likes blues, and stuff with lots of vocal harmonies, like the Beatles and Beach Boys, and my mum was into Abba, Hot Chocolate and lots of Joan Armatrading.
The household I grew up in... was like a building site. My dad's a plumber and electrician, and they bought this house planning to convert it, but then my mum got pregnant and they never finished. So we live in house that's like two flats – two kitchens, two bathrooms, two front doors.
When I was a child I wanted to... I've always known I wanted to do something musical. My auntie plays the trumpet and had a piano in the house, which is why I started.
If I could change one thing about myself... My forgetfulness. I forget everything – it goes in one ear and out the other. My brother's the same; I blame our parents!
You wouldn't know it but I'm very good at... throwing a party. I had one for my 18th, it was very memorable – my mum got me a stripper.
At night I dream of... I used to dream when I was younger that I was stuck in the vampire-themed page of a Where's Wally? book. I used to dream it literally ever single night.
I wish I'd never worn... When I was about 14 I had a bandana. All my friends had them too, and visors as well – I had a pink visor.
What I see when I look in the mirror... I'm all right with looking in the mirror. I've come to terms with what I've got and realised I can't really change it – I wouldn't be one of those people who have plastic surgery.
My favourite item of clothing... For my 'Easy Please Me' video, we had a Mulberry coat, like a really bright orange one – that's going to come out on special occasions.
It's not fashionable but I like... tracksuits. When I'm travelling or getting a plane, I get my tracksuit out. They're so comfy. Why can't they be the thing everyone wears all the time, instead of jeans?
A book that changed me... The Kite Runner: I read that last year and it made me think about guilt differently.
The last album I bought... The Light of the Sun by Jill Scott, and Beyoncé's 4 as well.
My secret crush is... I have a few. I can't say because I'll be too embarrassed if I ever meet them... James Franco is the most beautiful person I've ever seen, but it's not really secret because everyone fancies him.
The person who really makes me laugh... My mum. She is literally the female version of Del Boy. She actually has a joke book and will read me really bad jokes out loud.
What's the point? Every time I get stressed out I think, 'Why? I am just some tiny little person on this earth, I'm so insignificant'. So I'm still trying to work it out.
My life in six words... Busy, ravey, laughter, up and downs.
A life in brief
Kathleen Brien was born in May 1989. She grew up in Peckham, south London. At 14, she went to the Brit School and, at 16, was a vocalist on DJ NG's 'Tell Me'. She received a degree in popular music at Goldsmiths in 2010. Her first single, 'Katy on a Mission', was a hit last year and her album On a Mission peaked at number two after being released in April. Katy B is nominated for this year's Mercury Prize, and is playing at The Big Chill Festival, today and tomorrow. She lives with her family in south London