Interpol: Sam Fogarino, Paul Banks and Daniel Kessler.

Interpol: Sam Fogarino, Paul Banks and Daniel Kessler. Photo: Eliot Lee Hazel

Paul Banks, dapper in a summer hat even in a winter chill at the Parklands home of Splendour In The Grass, is not long away from going on stage at the festival. He had been a bit distracted but now peers sceptically at me.

I had described a disturbing moment a night earlier when his band, Interpol, were playing in a modest Byron Bay pub and I was sure he had smiled. A proper, I'm-having-a-good-time smile.

"Where was that?" he asks suspiciously. "Oh right. Well, I might have been cracking up because of something going totally wrong technically at that time."

No, I tell him, you looked genuinely happy. Which he is entitled to, of course, even for a band who mastered stern looks and trouble-me-not-with-humour stage personas early on in their updating of chilly but compelling dance rock.

Banks concedes this but then conspiratorially shares a tale of a fan who maybe got into the usual Interpol spirit a little too much.

"I had some guy grabbing his girlfriend's naked boob for an entire concert in Europe recently. In the front row. And he was staring at us, like, really coldly while he did it, like 'does this offend you?' " says Banks, perhaps unintentionally slipping into a German accent for that last bit.

"And I cracked up for the first three songs. Couldn't stop. I finally did stop looking but I had confirmation later that he did it for the entire show. It was somewhat confrontational."

When there is a certain tone to a band's songs, it's probably to be expected an audience's response will reflect that, but this might be taking the coolly distant but nonetheless intense nature of Interpol songs a step beyond.

The breast mangler aside, how does Banks deal with or respond to that energy coming from the audience?

"I just respond to physical enthusiasm. I don't really focus that because I'm having an experience expressing the music, and the more into that experience I am, the better it is for the audience," he says. "So I'm not the best at talking or interacting with an audience, but I think that giving your all is all that people really care about anyway."

If you've ever seen Interpol, you probably didn't want Banks chatting in any case, breaking the mood with banter. Keep that for the dressing room, don't break the spell.

Of course the dressing room in recent times has had some of its own issues, with original member and bassist Carlos Dengler leaving in 2010, drummer Sam Fogarino declaring that the members "need a good break" and both guitarist/singer Banks and guitarist/principal songwriter Daniel Kessler taking on solo projects.

Banks says he needed the solo project as an outlet for his own songs but never doubted during the four-year hiatus they would reunite, as they did earlier this year for the recording of what is their fifth album, El Pintor.

Without Dengler, it started slowly, things not quite gelling, until Banks brought in a bass guitar on the second day and took on that role in the studio.

"The question was 'could we write songs without Carlos?' and that was resolved day two," says Banks.

So was Dengler's departure a catalyst for new Interpol or merely a shift internally?

"I wouldn't be picking up the bass if Carlos hadn't left the band," Banks says rather obviously. Well, yes – but was this the change they had to have?

"In so far as it was his choice."

Pause. Silence.

And that's all he's going to say on the matter as, with the merest flash of a smile, Banks stands up and heads towards the stage.

Interpol's El Pintor is out September 5.