How did joining The Sugababes at 21 change your life?

"Coming from a small town, Aldershot, it was quite a change.

Before, I was a struggling singer. I got a solo deal with Telstar but I got dropped. I formed a band called Boo 2, got a deal with Telstar again, but they folded and the thing is how hard it is to keep going, but even if your confidence goes down, you must keep kicking ass. The Sugababes manager saw me a couple of years ago and said he had something for me, and I nearly had a heart attack, having to sing three songs with Heidi.

Keisha heard them the next day and had to decide if she liked me."

The Sugababes have undergone several changes in personnel. How have you settled in?

"I don't pretend I'm anyone else.

I'm not anything like Mutya, I have my own voice, I just try to be myself. I'm a bubbly person, not afraid to say what I think. I have a weird sense of humour and not everyone got it at first but then they got to know me."

How would you define the essential characteristics of The Sugababes?

"We're like three solo acts in a group. Our looks are so different; our voices are different; our skin colours are different."

The Greatest Hits Tour will be The Sugababes' first headline tour of arenas. How will the live show change from the past?

"Playing big arenas definitely affects the choreography, and there'll be a different song order, adding a couple of new songs that I've not sung before. We're very excited to start the show with Red Dress, which gives us an upbeat beginning.

"But the main thing for our show is that it's still about the vocals, not hardcore dance. We're not going to pretend we're anything we're not!"

Who came up with the suggestion for The Sugababes joining up with Girls Aloud to record Walk This Way for Comic Relief?

"The idea came from Richard Curtis, the Comic Relief founder.

We thought it was a brilliant idea, but it had to be the right song.

"As soon as Walk This Way was put to us, we could all see Girls Aloud being rocky and us doing the chilled-out bit. I'm quite good friends with Sarah Girls Aloud's Sarah Harding, and we definitely played on that thing of people saying 'you can't play with them' by playing up the Battle of the Girl Bands."

The battle theme is played out amusingly in the video, isn't it?

"We filmed it at a massive warehouse in London, where they'd built this set-up of separate rooms for the bands, back to back. It was a long day and night's work. I got up at four in the morning; picked up at quarter to five, and we didn't finish until 2.30am the next morning. It was quite hardcore!

Everyone gets a bit delusional after a while!

"But all we want to do is raise as much money as possible to raise awareness of the needs of children in Africa and in this country."

After the Greatest Hits Tour, what are your recording plans?

"We've started to write new material and we're booked in for sessions all over the place. I'd like to put my stamp on a few songs. I'm a songwriter, and I'm happy to be able to make my mark."

The Sugababes, Greatest Hits Tour, Sheffield Hallam FM Arena, tomorrow, 7.30pm. Box office: 0114 256 5656