She could be fluttering around the globe with the Puppini Sisters, charming audiences with songs from their new album, Hollywood. Her life could be so serene. But would she be happy?

Hell, no. The Puppini Sisters are Marcella's bit of fun. Now meet her real band, the Weimar-inspired art-indie-rock outfit of misfits and drama queens with whom Marcella can tear open her soul.

Marcella and the Forget Me Nots may be glamorous, but they're not lovely or charming. They are a scream in the dark, a pulse of desire, the glint of a knife. And they are Marcella's pride and joy.

So much so that Marcella refused to sign with a label for the band's debut album, Born Beautiful: instead she is releasing it independently – with the help of fans who donated funds via PledgeMusic. She knows from her experience with the Puppini Sisters how easy it is to be trapped into one sound, one style.

With the Forget Me Nots, Marcella has the freedom to explore the full range of her musical loves, from opera to big bands, Klaus Nomi to PJ Harvey, David Bowie to the Dresden Dolls, fusing these disparate influences with her own unique style to create something boldly individual and new.

Born Beautiful is her statement of eclectic intent. The title track is a cry from the heart: a plangent piano ballad that explores, with unflinching honesty, what it feels like to be “a prisoner of my insecurities”. Marcella's arrangement is exquisite: restrained yet fierce, gently propelled by Amy Kelly's militaristic drums and illuminated by Kati May’s golden clarinet solo. Opening song She Hero (key lyric: “She has the strength of a warrior, she shows the way to be free”) could hardly be more different: it's raw and sassy, Marcella a sultry banshee over Pato Vidal's strutting bass. And closing song Run While You Can is different again: while Marcella sings – true story, this – of her siblings seeing the devil in the Italian countryside, Ping Lee evokes those dark, open spaces with guitar-playing worthy of Ry Cooder.

With every arrangement, Marcella conjures up a new mood. Lullaby is as soft as its name, a swirling dance of clarinet and strings, so romantic you could almost miss the violence at its heart: “As you sleep your blood will dry,” Marcella croons to the philandering lover she has just murdered, “until it runs no more.” To The Water pulses with drama, Marcella's voice aching over a chilling backing chant of “Dies Irae” and Geri McEwan's stabbing violin. Dirty Old Men, meanwhile, is just plain twisted, a playful, sumptuously orchestrated serenade to all the sleazy geriatrics Marcella encountered in her youth, jacking off in the ladies' toilets or pressing up against her on the bus.

The two Marcellas seem so unlike, they might be different people. But this is typical of Marcella’s ability to metamorphose, her quest for self-reinvention. It started when she abandoned an idyllic existence in Bologna, Italy, for London and the notoriously fraught life of a fashion student at Central St Martins School of Art. In Italy, she was a lady cultured in the classics: ancient Greek, Latin, the history of art. In London, she transformed herself into a doyenne of modern punk, graduating from her degree course to a place in Vivienne Westwood’s production team.

But deep down, what Marcella really wanted to be was a singer. She sang throughout her teens: in covers bands, in madrigal choirs, in an all-girl punk outfit called Dead Sex Kitten. And after two years with Vivienne Westwood, Marcella knew it was time to shed another skin. She turned her back on fashion and embarked on a new degree, in jazz performance and composition at Trinity College of Music, which led to a successful stint as a jazz singer.

It was during this time that Marcella encountered the new burlesque scene, the alternative performance artists transforming cabaret for the 21st century. Here was the catalyst for another reinvention. Marcella began collaborating with similarly strong-willed and provocative female artists and entrepreneurs, including Marisa Carnesky and the Whoopee Club, for whom she became the in-house songwriter and musical director.

And, enlisting two singers from Trinity, she formed the Puppini Sisters, a tongue-in-cheek trio modelled on the Andrews Sisters, who dressed in meticulous vintage outfits and sang modern pop – anything from Beyonce’s Crazy in Love to, their piece de resistance, Kate Bush’s Wuthering Heights – in a gorgeously fluid, exquisitely harmonised style.

The Puppini Sisters almost pinned Marcella down. The trio became dizzyingly popular, earning a gold disc for their debut album and performing around the globe. But at the height of this success, Marcella began plotting her next, most challenging, reinvention. Something that would allow her to explore the diversity of her musical inspirations: from 1970s art-rock to opera, from Punk to Klaus Nomi, Nick Cave to Amanda Palmer. Above all, something totally, unflinchingly personal.

And so Marcella and The Forget Me Nots were born.