I'm half expecting Lykke Li, a 22-year-old Swedish pop sensation, to be precocious. She's said that she wants to be the next Madonna, but there's something unassuming about her as she stands in front of me, looking melancholy. She is twiddling a necklace with her name spelt out in gold, from New York, where she lived for three months at the age of 19, and her legs look long in thick, black tights with open-toed wedge sandals.
The otherworldly, child-voiced starlet has just released her debut album, Youth Novels, which sounds like ethereal disco for the broken-hearted; she has been touring the UK and will play Glastonbury this weekend. The night before our interview, I watch her perform. Casting a spell over her audience with her sweet, fragile voice and holding a glittering purple tambourine, she sings, whispers, squeaks, hiccups and coos from behind a curtain of long blond hair. Both self-contained and wild, she indulges in crazed bouts of head-banging reminiscent of Meat Loaf, before stretching out her arms, grabbing at nothing except strong emotion, like a young Kate Bush.
"I want people to have a good time," says Li later. "It's boring only to hear singer/songwriters spilling their guts." Her varied stage personae are all part of the "many different sides" to her personality. "I am such a complex person. I have so many different layers of my personality to choose from," she says. "I am super-sensitive and I am super-strong."
The songs on her album are all about love and heartbreak. The little girl's pop lullaby "Dance, Dance, Dance", the sweet "Let It Fall", documenting a break-up, the beautiful "Tonight" and the latest single, "I'm Good, I'm Gone", communicated partly through a megaphone – all document Li's life like a diary, seamlessly mixing pop, soul, folk and hip-hop, not to mention an assortment of sounds created not only by her voice, but also with foot stomps, chimes, theremin, flute, kazoo and harpsichord.
Li's EP Little Bit was released first in Sweden on her own record label LL Recordings, then by Moshi Moshi Records, who also pioneered Kate Nash. Li then took the finished album to Atlantic, part of Warner Music, who snapped her and her record label up, under an exclusive licence.
Li was born Li Lykke Zachrisson in 1986, in Ystad, Skane, in south Sweden, and moved to Stockholm as a toddler. Life growing up with hippie parents – her mother Karsti Stiege is a photographer and her father Johan Zachrisson a musician – was never conventional. Along with her older sister, Zara Lou, 26, and younger brother, Zacharias, 19, they upped sticks and relocated to a mountaintop in Portugal for five years when Li was six years old, followed by stints in Lisbon and Morocco, then back to Sweden. The family all headed to India in the winter months.
Last summer, Li was working in an old people's home. In the past six months her life has changed dramatically, after a period of utter despair. "I thought my career was never going to happen!" Now she is on the road, touring until New Year's Eve. She has no base. "Where do I live? That's the thing I don't even know myself. I don't live anywhere. I have always dreamed of moving out of my country because Sweden is boring." She keeps some possessions at her brother's apartment in Stockholm and thinks she may end up in New York – although she likes the sound of Argentina, too. "I like adventure," she says.
She leads a wholesome life: her favourite food is sushi and she enjoys walking. "I didn't drink alcohol for a few years. I made an exception for champagne. I was so tired of people hiding behind alcohol. I didn't want to be the kind of person who didn't have the guts to do stuff without it." Her heroes are Edith Piaf, Joe Strummer and Nina Simone. "Everybody who took a chance. I think every big artist doubts themselves because it's a journey. But they had a message, a good soul and they wanted to give people something."
Li wrote most of the 14 songs on her current album in two months. "Everything I write about in the album – all the heartbreak – has really happened to me. I wanted it to capture a time in my youth that was reflective, but it is recorded in a way that is fast and instant. I wanted to get my music out there without dwelling on it for too long."
Part of the complex problems that surround her love life, claims Li, is that she feels like "an old soul". "This world consists of having to go to parties and talk about the weather. I can't do that and it is very hard and it can be very lonely for me. I struggle with myself every day – I am a lonesome person. I talk to my family – and I connect to some people deeply along the way – but I am a restless soul. Singing is the most immediate relief. It allows me to be free and you can touch people with your voice. It feels good – like crying, almost."
The album's heartbreak is largely focused on one "really weird relationship" that tortured her heart. "It's been and off for three years. We've never called each other boyfriend and girlfriend – but, I mean, we've done everything else," she laughs. "Some guys have their heart broken and they never open up again. He just wants to party and I'm so over that. We were on different pages in life and we had this really strong connection. I have a really hard time finding anybody that I like; this loneliness I express on the album is because it sometimes feels like everybody has somebody."
Can she explain the fascination people have with her? "I talk about things people don't expect me to talk about. I wish I didn't think so much. I wish I was happy and dumb. When you look at me I look like a 12 year-old girl with this baby voice who hasn't been through a thing in her life, but it isn't true."
Youth Novels is out now on Warner; Lykke Li plays Glastonbury on Saturday (www.glastonburyfestivals.co.uk)