"Even though it's heavy, when I'm done I feel so much better. It's such a release."

Sharon Van Etten is talking about 'Your Love Is Killing Me', the most immediately bracing song from her new album, Are We There. In fact, it's her immediate response to which of those songs she's most looking forward to playing live. It confirms something she has made clear for a while now: that music is her catharsis, her way of dealing with the sadness and disappointment that informs her life.

It's an uncharacteristically temperamental Friday afternoon in Barcelona, and we're sitting in the lobby of a seafront hotel just down the road from the sprawling Parc del Fòrum, where the 14th edition of Primavera Sound is in full swing. It's Van Etten's second time at the festival (in 2012 she took the crowd by surprise by sarcastically proclaiming the city "ugly" almost as soon as she took the stage), and she and her band arrived in the early hours of the morning after driving straight through from Paris.

Having only seen confirmation of the interview a couple of hours previously, I scrawled some thoughts into my notebook on the taxi ride down, and upon arriving at the hotel am quickly met by the singer. She is tired but relaxed, and makes for an exceptionally warm, inviting interviewee: self-deprecating, quick to laugh and disarmingly open.

Live version of 'Love More' from epic

She shares that latter with her songs. Throughout Van Etten's discography, from 2009's stark Because I Was In Love to her comparatively lush, expansive latest, she explores heartache and the difficulties of maintaining relationships in a frank, unapologetic tone. That tone ranges from the seething (as on the clattering 'Serpents' from 2012's Tramp) to the wounded and self-critical ('A Crime', which opened 2010's epic, fearlessly sifts through the fallout of a poisonous relationship).

'Your Love Is Killing Me', a cavalcade of glistening electric guitars, organs and marching drums, puts physical violence front and centre, but here, at least, this violence is more obviously figurative than in some of her material. That doesn't stop it being an uncommonly forceful six-and-a-half minutes, though. The song, as with Are We There as a whole, reflects the problems she has faced in terms of balancing life as a touring musician with being committed to a long-term relationship, and when I ask her about these themes, she becomes understandably downcast.

"Well…" she begins. "I'm just at the point where, basically, my boyfriend of ten years and I ended up breaking up, because he couldn't handle this… this life. I'm gone nine months of the year. How do you be a good girlfriend - or even friend or daughter or sister - when you're gone that often, and unreachable half of that time?"

Interviewing bands and singers is a bizarre thing, sometimes. For just a little while you're given a window to their world and their art - people who you've never met before, and may never meet again - and often end up discussing some of the most personal things. Speaking with Van Etten about the dissolution of a relationship that clearly meant a great deal to her is something I immediately regret instigating, but it is something inextricably tied up with where she and her music are at at the moment, and she continues apace.

'Our Love' from Are We There

"I'm still learning how [to tour]. Most of my friends and family, they understand it and they get it; they're supportive and they know that I wouldn't be okay if I couldn't perform and write and do this, but it is hard. I write all these love songs, the irony now being that what I write about isn't really…" Here Van Etten trails off for the first and only time in our conversation, so I ask more specifically about what it's like to go on tour, and be staring down a lengthy cycle in support of the new album. Does she enjoy life on the road?

"I do!" she says, enthusiastically. "I feel like it's a double-edged sword because I love my band. They're some of the most beautiful people -" at exactly this point her band walk into the lobby, delighting Van Etten - "- right on cue!" she laughs, introducing me to guitarist (and artist in his own right) Doug Keith. "They're some of the most beautiful people I've ever met," she continues, after making lunch plans with Keith. "I wouldn't be able to keep going if it weren't for them."

She goes on: "In a way it's more intense than being in a relationship: you're working together, living together, you're put in stressful situations, sometimes on no sleep and hardly any food, you know? But they're really supportive, and they understand me."

Keith, multi-instrumentalist Heather Woods Broderick and drummer Zeke Hutchins are part of Van Etten's touring band, and all feature on Are We There, an album which, 'Your Love Is Killing Me' aside, replaces Tramp's sharp, jagged musicality with something that is somehow both softer and grander all at once. Strings and horns are expertly deployed throughout, while electronic beats click and whirr unobtrusively in the background of songs like 'Break Me' and 'Our Love'. To me, though, it's the rousing, unhurried 'Tarifa' that is more emblematic of the album than any other.

The song is named after a small Andalusian town located on the southernmost point of Europe, which Van Etten visited immediately after wrapping up her European tour of a couple of years ago. "My boyfriend and I rented a car and drove down the coast of Spain, and that's where we ended up. We stayed there for a week," she explains. "That was the first time we had a trip together, and I've never seen him so at peace. That's where I wrote that song. On a fucking cliff, like, overlooking Morocco! It was really special… just me and him, and nature. It was exactly what we needed to reconnect."

The song is, fittingly, a beautiful one, and testament to a memory that Van Etten holds dear. It is notably uplifting, too; for all the heartache and hardship evident on the album, it rarely comes across heavy or bogged-down, an impression that the relatively lighthearted 'Every Time The Sun Comes Up' only reinforces as its finale. Van Etten is pleased the album is finally out there, and when I talk about how positive the reaction has been and ask if she keeps up with what people are writing about her, she laughs and says that she has long-stopped googling herself.

Her attitude towards cover versions is a little surprising, though, given the indelible versions of Nick Cave & The Bad Seeds' 'People Ain't No Good' and Bruce Springsteen's 'Drive All Night' she has delivered over the last couple of years. "Those were fun to do, but… I feel so self-conscious when I'm playing covers. I'm always afraid I'm going to offend whoever wrote the song."

'People Ain't No Good', performed in session for Australia's Triple J

"I think if I were to do more covers, I'd like to do something more current," she tells me, perhaps mindful of Bon Iver's version of her own 'Love More' that boosted her profile a few years ago. "I feel like people don't do that as often anymore, and to cover someone contemporary to maybe turn more people onto them… I feel like in that way maybe I could help."

Does Van Etten write on tour? She gets out her notebook, and tells me that she writes all the time. "Basically, when I'm alone I record demos, but I don't listen to them. Then I bring them on the road and I put my headphones on and do the lyrics. If I come up with ideas when I'm on the road then I'll try to demo more on the road, so when I get home I can give myself assignments based on everything I have."

She has, by her reckoning, accumulated some hundred or so of these song sketches since last November. I put it to her that that's quite a lot, to which she responds emphatically: "Yeah. I mean, there's a lot of shit, but…" She flicks through her notebook while elucidating her method. It's crammed with notes and numbers, all written in the same handwriting that appears on the cover of Are We There: "I number them… Here's a cover, [where] I had an idea for something… Here's, well. Nothing interesting here," she says, showing me an almost blank page. "This one kind of sounds like Beck, but I don't really know…" she goes on, leafing to a far busier one. "When I get home, I have a priority list. If I don't have tasks, I won't do anything," she concludes.

Later that afternoon, Van Etten practises her Spanish on the crowd amassed in front of Primavera Sound's ATP stage, sincerely apologising for comments previously made at the festival (doing her level best not to dig herself into an even deeper hole this time round) and offering a very fine set indeed. At one point she bids her band farewell in order to play a solo 'I Know' at the electric piano, a song that she had earlier expressed reservations to me about performing. I had asked specifically about it only because it's such a stirring vocal performance; she had countered that perhaps it wasn't really the kind of song that people would want to hear at a festival.

'I Know' performed on Later… With Jools Holland

"I sing about my fear and love and what it brings," she imparts near the song's beginning, after inviting her audience to "get down" with her. ("And I don't mean get down as in party," she qualifies.) It's a powerful moment, and one that feels commendably intimate given the brightness of the evening and the size of the stage Van Etten commands. "Hold on, hold on," go its closing lines, "All I ever wanted was you."

Never mind that these lyrics could be lifted from any pop song of the last 75 years: by way of her remarkable voice and presence, Van Etten imbues sentiments like these with such weight and meaning, it's like hearing them for the first time all over again.

Sharon Van Etten plays Green Man tomorrow, her last date before starting a tour of the US, Canada and Europe in October; head to her website for full details