Jessie Ware is a proper pop star. With her soulful, melancholy vocal, effortlessly elegant songwriting skills and, of course, that striking slicked-back hair, she marks a new era for pop. Her outstanding debut album Devotion combines the ultra-modern feel of downtempo R&B and British electronic music with the melodrama of classic stars like Sade and Whitney Houston. “I’m ready and excited,” she says, of her impending stardom, before chucking in an earthy, “And I got to make a bloody lovely record, with people who are lovely, so I need to enjoy it!”

But it nearly didn’t happen at all. South London born Jessie started singing at school, inspired by the romance of her mother’s Frank Sinatra and Ella Fitzgerald Sings Cole Porter tapes, appearing in musicals and picking up some classical training along the way. But then she got to university and her life began to veer in a different direction. “I didn’t think it was ever going to be possible,” she admits, having put her dreams of being a singer on hold. “It always broke my heart a bit. I couldn’t even do it as a past-time, because it made me feel too sick to only half do it.”

Instead, she pursued an alternative career as a journalist – “I wanted to be a football reporter for a red top,” she confesses – until a chance phone call from her old friend Jack Penate changed the direction of her life again completely. He remembered she could sing from school, and asked if she’d do backing vocals for him on a Zane Lowe BBC session. She leapt at the chance. “I thought, this is brilliant, it’s really fun, singing,” she recalls. “Maybe I could be a backing singer.” Jack took her on tour with him, at first around the UK festival circuit, then to America.

In the States, Jack’s guitarist introduced her to the music of a new producer he knew, now going by the name SBTRKT. He lived down the road from her in Tooting, and as soon as she got home, she went round to his house. “I didn’t think I could do it,” she admits. Appropriately, they ended up writing a song called Nervous. “It ended up being a lead vocal. SBTRKT sent it to Numbers, who wanted to put it out. He said, ‘Because this is a lead vocal, we should have it as SBTRKT And Jessie Ware, not just featuring.’ I thought, this is amazing. I’m going to have a song on a really cool label, and whatever happens, I’ve got a vinyl.”

Thankfully, and obviously, things didn’t stop there. On the back of Nervous, DJ Oneman, of dubstep/grime station Rinse FM, invited her onto notorious urban live stream the Boiler Room for one of its first ever PAs. She hooked up with Sampha, who had also sung on Nervous, to write Valentine, one of last year’s sweetest tracks, all breathy vocals and beautiful simplicity. Armed with those two songs and riding a growing wave of hype, she was snapped up by brand new label PMR.

With her name on everyone’s lips, the time seemed right for an album. But, despite another big guest spot on Joker’s The Vision and standout vocals on a number of tracks on SBTRKT’s debut album, Jessie wanted to make sure she was truly ready to go it alone, and to forge her own sound. “I needed to take a step back from being a dance vocalist,” she explains. “As much as I love the underground scene and was lucky enough to be accepted by it, I wanted to set that apart and learn how to be a classic songwriter. It meant working hard, because I didn’t want to put out crap. I wanted a bit of longevity. I didn’t want to be a flash in the pan.”

An intimate gig at the Nave church in Islington in March 2012 marked the moment it all came together. Looking every inch the classy pop star, Jessie unveiled her new sound, with the help of her own live band. “It felt really special. I felt like people were there for me, not just as a backing singer or doing a PA for one song in a club then buggering off.” Those expecting a beat-driven, funky/garage-influenced sound may have been surprised by what they discovered. “I wanted to combine electronic with a more classic songwriting,” she explains. “I didn’t want it to feel too ‘of now’, so that’s why I went back to beats and grooves of things I loved before, like Prince and Chaka Khan and Grace Jones. I wanted to make downer R&B, and songs that are beautiful and bittersweet, like Sade. It was just about mixing it up in the right way.”

Her debut album Devotion contains that effortless poise within 11 laid-back, soulful pop songs that run the spectrum of sweet and dark. “I feel like I’ve been allowed to push it with the melodrama,” she smiles. “Like [early single] Running was me thinking of Whitney Houston’s Queen Of The Night and romantic film scenes from the 80s, where the guy sees the girl at the prom…” The title track, she says, is the first song she wrote with Dave Okumu from the Invisible, who would become a key part of the making of the album. “That’s why I wanted the album to be called that, because it’s where it started. That’s when I felt like a singer, and could express myself in the way that I wanted, with the music I wanted.”

The upbeat nu-soul swing of Sweet Talk (“one of my favourite songs”) is about someone trying to pull you in even though you’re trying to stay away, sung with flirtatiousness, but also a hint of danger. Night Light may seem dark, with its remarkable and dense shimmering layers and lines about shadows and ghosts, but actually, Jessie says, “the essence of it is very sweet. It’s about my boyfriend, and being scared of the dark, and him just… being there.”

Devotion takes a look at other relationships, too, not just romantic ones. Next single, the tentatively desperate Wildest Moments is of particular significance to her. “It’s about my relationship with my best friend. We love and hate each other. I never fight with anybody more than her. She’s the person who told me I was an idiot and asked me why I wasn’t singing when I have a voice, so she means a lot to me… It’s about those extremes of being amazing and awful together.” Taking In Water, meanwhile, all powerful choral melancholy, is a message of support for her younger brother. “I’m proud of that one because it’s really emotional. My brother was going through a hard time, and I love him dearly, and we’ve never been very good at speaking to each other, so I put it in a song. I don’t even think he’s heard it!”

Pulling it all together with a uniquely Jessie Ware sound were her producers Dave Okumu, Julio Bashmore and Kid Harpoon. “They’ve been my three people for this album. I like that they all bring something different out in me.” But it’s Dave in particular who seemed to tease all of her potential out into the open. “I couldn’t have done the album without him,” she says. “He’s taught me so much. He reads my mind. He’s the best person in the world.”