Devendra Banhart is having a cry. Not a huge one. One small tear and it's over.
"I told you this would happen," he says, blinking. "Didn't I tell you?"
It's true, he did. An hour earlier, shortly after Banhart finished an interview with the radio presenter Lauren Laverne on BBC6 Music, during which his mind appeared to be elsewhere, he told me: "I find talking out loud, even to my friends, really difficult. And my friends would tell you that I will cry eventually. Not because I'm self-conscious. I know I'm an idiot and there's a liberating aspect to that. I just get teary at the most inopportune moments. It's like, because it's not really the time or place to be doing that, it just sort of happens."
There's something of Woody Allen about the 31-year-old Banhart, both in his compulsive self-analysis and his amusing line in self-mockery. All this is far removed from his image as a serious singer-songwriter and barefoot hippie dude who has been quietly bewitching the world of music for the past decade.
The Texas-born, Venezuela-raised Banhart is part of a loosely-connected generation of singers – among them Sufjan Stevens, the harpist Joanna Newsom and torch singer Antony Hegarty – that have made unexpected inroads into the mainstream. While his early albums have been credited for blazing a trail in 'freak folk', he prefers to classify what he does as "unpopular pop music".
Of his contemporaries, Banhart is the most prolific and successful, his musical eclecticism and keening vibrato being fêted by the New Yorker as belonging "in a universe of its own". He has recorded with Beck and Wu-Tang's GZA, founded a record label, performed at New York's Carnegie Hall and, briefly, dated the actress Natalie Portman (she appears in the video to his 2008 single "Carmensita"). Lately, having cut his hair and ditched the hippie aesthetic in favour of something more dapper, Banhart has been fronting an advertising campaign for the hip fashion chain, The Kooples, alongside his fiancée Ana Kras – a sure sign that he has arrived.
But there is more to Banhart than music and looking pretty on billboards.
In the past 10 years he has pursued a similarly successful and completely separate career as an artist, having had exhibitions at the San Francisco Museum of Modern Art and the Los Angeles Museum of Contemporary Art, and collaborated with Yoko Ono. Banhart, who creates the artwork for all his albums, was also nominated for a Grammy for the haunting cover of his last LP, 2009's What Will We Be. It remains to be seen whether he will win prizes for the pink-hued cover of his forthcoming LP, Mala, which he enthusiastically describes as "water in a room full of ham".
It is Banhart's love of art that has led us to where we are today: London's Tate Britain. Given his lethargy during the radio interview, I hoped it might perk him up. This was both a good move (he is tremendously and vociferously pleased to be here) and an idiotic one (every time the conversation gets interesting, he gasps at a painting and bounds off to take a picture of it). But still, he reckons I could have gone one better with the choice of venue.
"We really should have done this interview in a massage parlour," he muses. "That would have been a treat for us both and then you'd have to write a nice piece because we'd be so relaxed. And we could still talk because they have those tables with a hole for your face. Has that ever happened before?"
It hasn't, I reply, but I did once do an interview, fully-clothed, in someone's bed.
"Really?" he replies. "Was that John and Yoko?"
No, I say. Jesus. I'm not that old.
"Oh no, that's not what I meant," he says, appalled. "I'm sorry. Oh anyway, you know what I meant. You're just trying to make me feel bad."
I am, I say.
"Well that's very British. But you should know I'm a horrible person to get in a fight with because I want to be punished. It won't be long before I cry again."
For someone allegedly uncomfortable with talking out loud, Banhart sure talks a lot. His conversation is fantastically random. We are, of course, meant to be talking about the new album, which is a terrific blend of alt-rock, synth-pop and Latin flavours, though he seems pathologically averse to the business of self-promotion. Instead, he picks up my Dictaphone and starts describing our surroundings – "So, we're eating lunch in the Tate Britain while looking at a print by Chris Ofili" – or reporting on my movements: "Journalist has stopped eating her sandwich. She complains it is full of gristle".
In a curious reversal of the interviewer/ interviewee roles, he also has a habit of jotting things down that he thinks might be of interest. By the time we go our separate ways he has written down Wolf Hall, Augustus Leopold Egg, Are You Being Served? and 'Allo 'Allo!. I fear that with the latter two I may have forever tainted his view of British cultural achievement.f
After lunch, he continues to pinball around the gallery snapping away with his camera phone and gasping, "That is so fucking beautiful". It's all I can do to keep up with him.
"The museum," he says, in a moment of seriousness, "is where I come to remember and to remind myself why I chose art as my religion. I'm not playing a role. This is truly the only thing that I care about."
In the late Nineties, Banhart was studying at the San Francisco Art Institute on a scholarship, but he dropped out so he could concentrate on making music. On the day his first record was released, he was also hosting his first solo art show. "Since then," he explains, "I've managed to have this parallel career in both worlds. I'll be playing a concert and someone will say, 'I hear you draw. Perhaps you should show your work sometime,' or I'll be exhibiting at a gallery and someone will ask, 'Do you still make music?'. These two worlds are totally isolated from each other, and I like that."
Given Banhart's own history, the polarity in his working life doesn't seem so surprising. Raised in Caracas by his mother and stepfather, at 13 he and his family moved to California. Banhart didn't speak a word of English but muddled through. Now he revels in his dual identity.
"Well I am a Gemini," he says. "And my two vocations aren't worlds apart.
"I believe we are all dual beings. Some cultures actually believe we have two souls. Also – and I think this is important – I was singing as a woman when I was a child."
Banhart explains that when he was eight years old, the ubiquitous music in Venezuela was salsa, merengue and cumbia. But then he discovered the existence of a rock radio station and, for the first time, heard Nirvana.
"And I'm thinking, 'Oh my God, this is incredible. That singing, how does he do that? It doesn't sound like that when I sing. What's wrong here?' I'm genuinely frustrated by the fact that when I open my mouth to sing, it doesn't sound like this guy."
So Banhart waited until his mother went out. He then put on one of her dresses, picked up a comb and sang into it as if he was a woman.
"It worked," he says. "It was like I had permission to sing the way I do. It was not a sexual thing. It was just that this part of me, the feminine part of me, said 'Hey, try this'. So maybe some of that duality comes from this initial experience. I was instinctively getting in touch with something that not everyone gets in touch with. If you wear a dress when you're eight years old it's kind of taboo."
Banhart had another epiphany, aged 18, when he was in Paris and "completely homeless. I didn't have a dime." He wrote to the folk singer Vashti Bunyan and, in an attempt to gauge his own musical potential, sent her some songs. She replied telling him she liked his work and encouraged him to pursue it. If it wasn't for that letter, he says, he would have given it all up.
Banhart's mother and stepfather were both acolytes of an Indian guru named Prem Rawat (aka Maharaj Ji) of the Divine Light Mission, who gave Devendra his first name, which is another name for the Lord Indra, the Hindu god of rain. His middle name, Obi, was his mother's idea. She was, it appears, a big fan of Star Wars.
The move to California in Banhart's early teens was an intense relief rather than an upheaval. "Caracas was a crazy place in the early Nineties. For instance, when I was 11 years old, I pierced my ear. No big deal, right? But everyone was so scandalised that they shut down the school. There were people phoning the school making death threats. It was like, 'Oh my God, there's a fag in the school'. So they actually shut it down."
When Banhart got to America two years later he was delighted to find that not only did he not have to wear a uniform at school, but all the boys had pierced ears. "No one was looking at me weirdly, I was free to be me. It was really very liberating."
Banhart's visits to Venezuela are increasingly rare. "It's home when I'm anywhere else, but when I'm there I'm a tourist. I go as little as possible. Venezuela is incredible, but Caracas? Oh God, I hate it. The sidewalks get smaller every time I go back. Now there's just these tiny little strips for people to walk on. The architecture is slowly evicting the inhabitants. Then there's the violence. Last year there were 69 murders a day. I know of an eight-year-old boy who was murdered for his shoes. I just cannot conceive of the frame of mind a person could be in to think it's easier to kill an eight-year-old than just take his shoes from him. It breaks my heart."
After a long period in Los Angeles, New York is now home for Banhart and his fiancée, whom he met two years ago when she, a photographer, was dispatched to his house to take his picture. I know this from watching their Kooples ad, in which they are interviewed about how they met.
Banhart, on the other hand, tries to convince me that Ana is a mail-order bride who has yet to be delivered. "They take a while to package them up," he explains. "And she's pretty big so…"
This, I think, is his way of guarding his personal life from prying journalists – that and legging it across the gallery when I'm mid-question.
What I do glean is that after 11 years of making music and art, he still believes himself to be an amateur. "I honestly don't think I've written a good song yet, and that's what keeps me doing it. It's the same with painting. I'm really just messing about with ideas, trying stuff out. One day I hope to make something really significant."
Even so, Banhart has a plan for when all the work dries up. "I'm developing this stay-together cure for couples," he says conspiratorially.
"This isn't your average snake oil that some voodoo man's going to sell you and then leave you at the side of the road with empty pockets. This is going to make relationships last and last. It's going to start off as an injection and then it will be pills. In the future you'll simply snap your fingers and download it. I've got a couple of secret ingredients, but the main treatment is that the male will take oestrogen for a week and the female will take testosterone. Worlds will open up and new perspectives will arise."
Nice idea, I say, though hasn't it been tried already? "Hey," he replies with a frown. "Don't ruin my dream. It's my ticket out of here."
'Mala' is out on Monday on Nonesuch. Devendra Banhart plays The Ritz, Manchester on 17 July and London's Barbican on 18 July. For more information visit nonesuch.com