Here’s a question: why don’t more musicians put more effort into live performance? I’m not suggesting they routinely fail to play to the best of their abilities, or that they take no pride in playing live. I simply wonder why for so many musicians playing live simply appears to be a matter of turning up, plugging in and getting on with it. There are “shows”, of course – the electronic artists who surround themselves with high-end visual effects to compensate for the fact that standing behind laptops does not a spectacle make; the arena and stadium superstars who have engaged in a production arms race that can make a big gig something akin to visiting a theme park – but how many times in a year do you go to see a band and watch them simply stand still? They play the songs, and it’s fine – sometimes it’s great – but they have given nothing of themselves. They could have been any three or four or five other people.

The reason for the question is that live performance matters. It matters more than ever before, because it’s how musicians survive. In February 2018, the UK’s first live music census found that performance accounts for 49% of professional musicians’ income; just 3% comes from recording. Then you’ve got to factor the fact that live shows are where most musicians sell the majority of their merchandise – and we’ve all seen how much busier the merch table is after an amazing gig. Every musician I speak to still counts albums as the markers of achievement, but the truth is that it’s much, much easier to make those albums when live shows have proved there is an audience for them.

This has been on my mind in the past couple of months, since I saw The Murder Capital for the first time, at End of the Road. I had liked their debut album, When I Have Fears, well enough – and people who like big, echoing post punk with intimations of doom liked it a great deal – but standing stageside in Dorset felt like being an unobstructed view of something cataclysmic. I say this with a clear conscience and no exaggeration: that Murder Capital show was the most exciting performance I had seen by a new band this century, for certain, and it went into the memory log with the best gigs I have ever seen. This is a promise: they were that good.

Could they be that good again, playing in London the other week? Yes, they could. The Murder Capital were astounding, on a plain stage in Tufnell Park: theatrical but natural, vulnerable and aggressive, and with a control of dynamics and tension that would put countless many older bands to shame. Theirs is a style of performance in which movement and stillness are counterpoints, and they are the only group I can think of in which the bass player (Gabriel Paschal Byrne) is as important a visual point as the singer (James McGovern). They are, genuinely, a pairing – only one sings, but they are both frontmen. (If my gushing isn’t enough, then consider that fellow tQ contributor David Bennun, reviewing their Brighton gig for Metro, decided: “Their show was short – under an hour – but it felt outside of time. There wasn’t a second of it that was not intensely riveting… They were, and are, extraordinary”).

“We realised after a couple of gigs that live performance was a strength we could nurture,” says guitarist Damien Tuit, belying his pre-interview shouts of “get the pints in!” by sipping Fentiman’s ginger ale as we talk.

“Also, it came out of the soundscape we were creating in the studio as we were writing and the songs we were making,” McGovern says. “They demanded a level of theatre. A lot of the music, to me, at times, is very dramatic. And the movements we started making, we started commenting on ourselves after shows, they were probably brought out of us by the music itself. I don't know if we ever spoke directly about what we were gonna do. It's more what we did that we thought was good. You notice things in yourself and what you do. And then if you see something someone else does … it's not about recreating, just about remembering something was great and filing it away. It doesn't happen every night.”

“The same thing never happens,” Tuit says.

“A lot of it can be subconscious, too,” McGovern reckons. “In the same way that if you practise any physical skill, the things that you are perfecting have such finite micromovements that you're not really conscious of them, but you know what didn't work well, or that maybe you just didn't feel right.”

“There are movements we've all done onstage,” Tuit says, “and afterwards one of us will be saying: ‘I don't know if that fitted that moment correctly.’ But it's difficult to describe, because it's something that comes very naturally to us, but it's also something we are aware of. We're at the point of: Are you going to change something because it will make the show better, or are you going to change it because you're bored?”

It feels odd to be asking a band barely a year into their career how they have constructed their show, what they wanted to bring to live performance. Not least because they only have ten songs – their album – and their live set is nine of those songs with the order juggled round. How they do what they do is evidently not something they have been called upon to articulate very much before. But what is evident in them is an unforced self-confidence that enables them to know exactly what they are without any hint of self-doubt, and that’s something that I suspect unites the best live performers.

For example, three years ago Bruce Springsteen told me about the E Street Band, and how it was apparent from very early on what he and his band were all about when they took to the stage: “I think my band strains to be accessible, to create another level of intimacy with the audience. We weren’t ambivalent about showing ourselves. We were never going to be the supercool mysterious artists, or the downlow independent heroes. That really wasn’t what we aspired to. We felt much more like your homegrown pub band, kind of on steroids. That brought with it a little bit of how you feel about your local musicians that you see down at the bar on Wednesday and Saturday night, which is who we were. And who we still remain to some degree. And that was the world I grew up in, so you live with your constituents, and they got to know you and you got to know them. It was just on Saturday night you’d get on stage and make the music while they’d be on the dancefloor. I got very used to that dynamic when I was very young – I did it for ten years before I signed a record contract, so I brought that with me.”

Equally, The Murder Capital have a very definite (and very different) view of what they are projecting from the stage. “I think it's vulnerability,” McGovern says. That’s one of the themes of When I Have Fears, an album informed explicitly by the suicide of a close friend, and the group’s attempts to turn a complex set of feelings into something that both reflected their experience for themselves while refracting it for listeners, creating something universal from the personal. But there are other things, too. “There are moments on stage when it feels like, to me, the performance is very sexual. It can be tongue in cheek, it can be facetious, it can be aggressive, it can be confrontational. You can have those things in the space of 60 seconds if you catch the looks.”

And there’s something else.

“You need to be menacing,” McGovern says. “It’s so hard to describe this, but if you don’t give the audience something they feel they have to react to… That menace and confrontation demands someone be left feeling intruded on. Maybe someone laughs to their mate and thinks it’s funny, but maybe their mate doesn’t think it’s funny at all. I feel like it corners you into a reaction. We’ve confronted ourselves so heavily in this record that it would be uncouth not to bring that to the stage.”

The confrontation is evident from the moment they take to the stage. While Tuit and fellow guitarist Cathal Roper, though constantly moving, seem to be looking inwards, McGovern and Blake are always looking outwards. It’s like a cavalry charge. “That first adrenalin rush when you come out makes you feel so primal and animalistic,” McGovern says. Tuit adds: “You wish you could just run and run and run and run, but you only have this much space.”

One of the boring, untrue assertions about rock and pop is that “it’s all about the music”. It’s never all about the music, as I have argued in tQ before. One of the thing’s it’s about is image. Every decision every band makes about how they appear onstage has been calculated to one degree or another. The group who amble on in their grubby T-shirts and ill-fitting jeans have chosen to do that. They have chosen to reject costume, just as the group in ridiculous silver and golden outfits have chosen to embrace it.

The Murder Capital, it must be said, look fantastic: McGovern and Byrne in suits, the guitarists in tailored trousers. I can’t tell you what the drummer, Diarmuid Brennan, was wearing because, well, he was behind his drum kit. After End of the Road, the small group I watched them with were discussing what they looked like: Peaky Blinders, said one; five Pinkie Browns said another; gangsters gone to a market town on Saturday night, suggested another. You’ll have detected the common theme there.

McGovern and Tait deny any contrivance in their appearance (and, to be fair, they look much as they do onstage, albeit they have just come from a photoshoot). “We dress in different versions of that in our daily life. As much as I am interested in film and literature, I'm equally interested in fabrics and clothing and style,” McGovern says.

“There's a freedom to being in a band. You feel like you're in a motorbike gang, especially when you're touring,” Tait says.

At which point, I’m afraid, I burst out laughing. “Oh, come on! You know what you look like onstage. You wouldn’t be the band you are if you dressed differently.”

“Definitely not,” Tait says. “But we wouldn’t be the same people. We wouldn’t perform the same, or talk the same. You’d be acting differently if you were sitting here in a matching Adidas tracksuit. You would talk differently and ask different questions.”

“It's just another extension of expression,” McGovern says. “It's no different from the books you throw into your brain. And the clothes you drape off yourself. I was into suits a bit as a kid. I had this brown wool suit from fucking Top Man when I was 17 or 18 and it was my prized possession. I saw a video of myself in that Facebook memories thing the other day. I was at a house party with my friends. Everyone is wearing Superdry jackets, and I'm standing there in a grey cardigan and a Winnie the Pooh tie. I feel like I had that shit forever. Who knows what we'll be wearing in 10 years? Fila? Kappa? Diadora? Sergio Tacchini?”

Of course, underlying all this is the question: did The Murder Capital decide they wanted to be a great live band, to look like a great band, to behave like a great band because that is the way to sustain a career. I mean that not in any cynical sense – but if you want to be great, you have to attract attention. You need people to spread the word about your greatness; you can’t decree it for yourselves. And you have to be able to survive; you have to make a living if you are to carry on making music.

Tait and McGovern seem horrified at the idea that anyone might think they are in a band for any reason so venal as wanting to reap rewards. Tait says they’ve never thought about live performance as a way of making up for the revenues bands can no longer make from album sales, and that rock bands especially find hard to garner from streaming services. He says that wanting to make music specifically to make money is wrong. “During the 90s with the grunge boom there were bands coming out of everywhere going, and you could be a rich rich rock star. That was never an option for us.”

“If there's ever a point in their lives when we can even come close to having a small apartment that's yours and you can fucking buy your food and still be in a band, that's the dream,” McGovern says. “The dream is to exist in this band. You can throw us into the 3 Arena in Dublin now, 12,000, a box room. And three or four of our tracks maybe wouldn't work in there at all. But what happens then, and we've seen it with many fucking bands, is that they start to write their music in accordance with their venue size. There's a lot to be said for knowing your room.”

Tait says he would be happy playing 500-capacity rooms for the rest of his life, if it meant he got to carry on making albums. That’s already a thing of the past. Last week they announced their next string of UK and European dates, and the venues have already got bigger – there are 1,500-capacity rooms among them. They are, right now, at the most thrilling stage of a band’s career – the part that always seeps with excitement decades on, when memoirs are written – when every single day seems like a step on from the last, when each crowd is bigger and more fervent than the last. They’re at that point where you can feel their brilliance, as much as hear or see it. Where you can sense the waves of excitement rolling off the stage and into the audience and back up from the crowd to the stage.

I didn’t realise before I saw them that The Murder Capital were the band I had been waiting for. I do try not to gush too much, but this band is truly great. They may not be great forever; they may start to hate each other; they may get lost in drink and drugs; they may lose the spark that right now makes them so explosive and scintillating. I hope not. They’re a band I want to invest hopes in. Don’t deny yourself the chance to see how great they can be.

When I Have Fears is out now on Human Season Records. The Murder Capital tour the UK from 14 February