“I’ve only ever been in a band with boys,” muses Ellie Rowsell. “It’s only when I go back home and hang out with all my girlfriends that I really think about how weird that is.” At 23, Rowsell is singer, lyricist and guitarist for Wolf Alice, the UK’s most exciting young rock band. Softly spoken and slightly bashful, her offstage demeanour barely hints at the dynamic range and energy of the group, encompassing dreamy introspection and fierce confrontation set to a thrilling, widescreen guitar attack.

Formed as a folky duo in 2010, Wolf Alice have expanded to a grungy quartet, coming up slowly through the backwaters of the British gigging scene. A smattering of critically admired singles and growing live reputation presaged their debut album, My Love Is Cool, going straight to number two in the UK charts in June. “It makes me slightly giddy. I remember working in shops and going a little bit crazy, just desperate to go on tour and into the studio, make albums and play festivals. And now it’s happening.”

This weekend, Wolf Alice appear on the NME stage at the Reading and Leeds festivals, where, it transpires, out of hundreds of acts, Rowsell will be a rare representative of her gender. The absence of female headliners has become a controversial feature of this summer festival season. A poster of the Reading / Leeds line-up was produced with all male performers taken out, leaving the page nearly blank.

“When I wanted to be in a band, I never thought it might be hard for a girl,” muses Rowsell. “But I find myself sitting backstage at a festival sometimes thinking ‘oh my God, I can’t see any women at all’. That’s insane. I’ve started to become a bit obsessed with women behind the scenes because actually you do meet female musicians, mostly solo or in pop, but you hardly ever meet a female record executive or a woman in the road crew.

And I wonder what their experience would be like? How can you have a whole industry that is male?”

Rowsell ponders these notions with a kind of airy innocence, rather than polemical speechmaking. “These are new thoughts for me. I don’t find it intimidating, because as an artist, you are the centre of things, doing something you love. But it might be scary to be the only woman in the crew.” She has noted that the media treat her differently to her band mates. “I don’t really care about fashion, I don’t always wear make-up, I don’t scrutinise outfits for hours. But I’m starting to think about it, which is a bit of a shame. The boys can wear what they want in photo shoots but I get asked to wear the latest collection from blah-de-blah or they want to do my make-up and it takes an hour. I treat it as part of the job but if you were insecure, it would be a headf**k.”

'We fit together': Wolf Alice Credit: Jenn Five/Jenn Five

Rowsell wraps her arms around her legs so that she is huddled up in a ball, head tipped to the side. It takes her a while to establish eye contact, but she gradually opens up. She has a gamine, slightly off-kilter beauty, the innocence of someone not entirely aware how striking she is, particularly in the context of a scuzzy rock band. “Someone asked me the other day whether I use my sexuality onstage, and I was horrified: ‘no, of course not!’ But it’s actually an interesting question. I would never force it, or use sex to get me somewhere, that would be weird. But I think performing you do feel quite sexy and powerful, and sometimes a line is crossed, it’s a natural expression.” She keeps coming back to the same basic point, with a sense of surprise: “I’ve never really had to think about these things before but I am thinking about them now.”

Rowsell attended Camden School For Girls, a north London comprehensive founded in 1871 by suffragette Frances Mary Buss, a pioneer of female education. “We were brought up to be aware of feminism but also not to consider yourself as a woman, in a way. You don’t play a gender role, you play the role of yourself. So I never felt much like a girl in the world. I felt like a person.” Rowsell is an interesting lyricist. She avoids cliché and has a deft sense of phrasing, delving deeply into things, asking philosophical questions and creating sharply observed narrative. Bros is a gorgeous, uplifting anthem to female friendship, You’re A Germ is an exultant put down of older boys preying on teenage girls whilst the epic Your Loves Whore dives head first into the gap between romantic fantasy and sexual reality.

In school she wrote stories and poetry, picking up the guitar at fourteen, later developing her songwriting with the garageband recording programme.

She idolised Kurt Cobain and fantasised about being in a band but her friends didn’t share her musical enthusiasm. At 18, Rowsell made her stage debut at an open mic night. “I was so bad, I literally couldn’t play guitar and sing at the same time.” She started searching for like-minded musicians on internet forums, hooking up with guitarist Joff Oddie (now 24), forming Wolf Alice as a duo. “That became a bit depressing. We wanted to make more noise.” Recruiting drummer Joel Amey (24) and bassist Theo Ellis (23) in 2012, a band was born. “We knew this was it very quickly. We fit together.”

Growth has been gradual, the calibre of musicianship taking time to catch-up with the quality of the songwriting. “We put ourselves out there as a baby band. If someone says ‘oh, I saw you two years ago’, I feel like apologising, but I’m proud of the journey. Honestly, if you saw Wolf Alice at the beginning, you’d be flabbergasted. We used to be so shit.”

They have come a long way. Like a band raised in the back room bars of Camden, the sound of Wolf Alice borrows unabashedly from decades of alternative guitar music, encompassing the dynamic quiet-loud switches of grunge, the jangle of indie, the epic sweep of arena rock, winsome intimacy of folk, mantric pulse of shoegazing, unison riffing of metal and even a hint of chilled out trip hop. “Is there any such thing as genre anymore? It’s all crossing, it’s a playlist culture. If you want to write a song that brings together Miley Cyrus and Metallica, who’s to say that’s wrong?”

Rowsell loves the very idea of a band as a group of like-minded musicians with a shared vision. “It would be hard to do this on your own. When things are going well, you can brag to each other, cos we’re all doing it, we’re in it together, going through exactly the same experiences. And you have people to pick you up when you fall, because it can be hard sometimes, being the focus of so much attention, not all of it nice. I don’t know how anyone does it on their own. I don’t know why they’d want to. It’s so much better as a band.”