Image copyright Virgin EMI Image caption Katy B's last album, Little Red, went straight to number one in the UK

Pop star Katy B on The Brits' diversity problem, working with Craig David, and (not) growing up.

Katy B x Craig David. Katy B x Major Lazer. Katy B x Four Tet.

That little x appears 22 times on the tracklist for Katy B's third album, Honey. Each instance signifies another hook-up between the London-born singer and another artist.

"I just love collaborating," she says. "I play instruments but my passion lies with my voice, so I lean on other people to do beats and instrumentals.

"I'm a bit of a frustrated rapper in that sense. The music speaks to me and gives me ideas. I turn it up loud and start dancing or humming melodies."

It's a technique that's paid dividends in the past. The star's biggest-selling single, Crying For No Reason, was co-written by Robbie Williams's partner-in-crime Guy Chambers, while her previous records have featured appearances from Iggy Azalea, Wiley, Jessie Ware and Ms Dynamite.

She have must the best contact book in the business.

"Haha! Yeah, I guess so," laughs the 26-year-old, sipping a green tea as her voice recovers from a day of tour rehearsals.

Media playback is unsupported on your device Media caption Katy B and Craig David perform Who Am I for BBC Radio 1

In reality, it is her association with Rinse FM - London's agenda-setting urban music station - that brought Peckham's Kathleen Anne Brien into the orbit of music's biggest stars.

Rinse gave the singer her first break when she was just 16 and the station was still a pirate outfit. Recording under the name Baby Katy, the teenager sent in a single called Heartache. She later described it as a "cheesy garage-type thing" - but it made station founder Geeneus sit up and pay attention.

"As soon as I heard her I knew there was something about her voice," he said. "I was writing a lot of grimy music, and the scene was all getting a bit overcrowded with men. We needed the girl element back in it."

Together, they recorded Katy B's first album, On A Mission, a love letter to dance music that nimbly straddled UK bass music and mainstream pop.

It was released just as the singer completed a degree in popular music at Goldsmiths, reaching number two in the charts and eventually being certified gold.

Nearly 10 years later, Katy still calls Rinse FM her second home. "Sometimes I'll just eat my lunch in there with the engineer who's working on the jingles," she says.

Being so close to London's underground scene, what did she make of the diversity argument at this year's Brit Awards?

"It would be nice for there to be a wider spectrum of representation," she says. "Grime is a genre that is fully British. It's ours. It's coming from our own people.

"That's what young people are listening to and that's what young people want to see.

"But then I've never been nominated for a Brit Award, either..."

Image caption "It was supposed to be four tracks and it turned out to be a whole lot more," says Katy B of her new album

Honey could be about to change that. Initially conceived as a stop-gap between albums "it turned out to be a whole lot more", the singer says.

Freed from the "pressure" of making a chart-focussed album, Katy cleaved closer to the underground scene than ever before.

A case in point is the sparse, bass-heavy Calm Down, in which the hedonistic protagonist of On A Mission confronts their late-20s.

"It's basically about when you're with your friends on a Saturday, but you've planned to go out with your other half the next day to buy furniture or something really boring," she says. "And then you're at the club just absolutely ruining it - so the next day you're like, 'Oh no, I can't make it to Ikea. I'm just going to stay in bed'.

"All my friends can relate to it. Like, when are we going to be those people that get up early for a run on Sunday rather than go out on Saturday night?

"I'm never going to give that up," she insists. "I'm going to be one of those crazy people at a drum and bass rave, aged 55, with my husband in a high-vis jacket."

The album's title track is more mellow - a sultry, steamy sex-ballad inspired by her love of 1990s R&B.

"I'm a big fan of slow jams," she says, reeling off names like Ginuwine, Jaheim, Faith Evans and Mariah Carey - who she is "100%" planning to see in concert this week.

"I'm there, mate, at the front. One of my best friends is a massive Mariah Carey fan, so it's like a pilgrimage. We're going to love every second of it."

Media playback is unsupported on your device Media caption Katy B performs Honey in the BBC 1Xtra Live Lounge

But while her formative years were soundtracked by tonsil-busting divas, Katy never tried to emulate their vocal style.

"My voice just doesn't sound that great when I try and sing really loud and high," she laughs. "It just sounds a bit like a cat being strangled - so I try to stick to the soft, sweeter tones."

She deploys those tones to devastating effect on her current single, Who Am I? Down-tempo and down-in-the-dumps, it discusses the consequences of a break-up - based on Katy's first boyfriend, who was also a member of her first band.

When they split, she explains, she felt she had to leave the group - and many of their mutual friends - and "start again from scratch".

It was originally written as a solo song, "but because the whole album is about collaborations, I wanted to have a male perspective on break-ups" - so she roped in resurgent soul star Craig David.

"Me and Craig had been working in the studio anyway," she says. "We've written quite a few songs together.

"So I called him up and said, 'do you want to be on the tune?' and he said 'yeah'. He re-wrote his verse and it sounded sick and I loved it."

And what of those other sessions? Was a lot of material discarded in the process of making Honey? It would appear so.

"I actually cried once thinking of how many tunes I've written that will never see the light of day," says Katy.

"I think that'll be in my will - to put all of my songs out there whether they're finished or not. Like, 'Here's the zip file. Download it now. Bish, bash, bosh'."

Who Am I? is out now. Katy B's album, Honey, follows on 29 April.