Let’s say you were a fan of Powderfinger and/or Something for Kate, two of the most successful groups from the post-grunge early 90s Australian music scene.

What would you expect an album made by their respective frontmen, Bernard Fanning and Paul Dempsey, to sound like? Acoustic ballads? Mid-paced, fire-up-the-lighters arena-rock anthems?

Well, it’s happened. And Fanning Dempsey National Park, as they’ve called their collaboration, is neither of those things.

“That wouldn’t be interesting for us anyway. That would be boring,” Dempsey says. Instead, they’ve zeroed in on the peculiar sonic landscape of the late 1970s and early 80s, with Dempsey developing “a pretty obscene synth habit”, collecting the gear that created the sounds both men grew up with.

The result is The Deluge, an album which harks back to Berlin-era Bowie, Gary Numan’s Tubeway Army, new-wave era Robert Palmer, Duran Duran – and Foreigner. Fanning gushes about Foreigner’s 1984 mega-hit I Want to Know What Love Is: “That song is such a masterpiece!”

The two singers go back at least 25 years, with Powderfinger and Something for Kate touring together periodically during their heyday and reconnect when Something for Kate’s last album, The Modern Medieval, was made at Fanning’s studio in Byron Bay in 2019.

It was then that the pair started bantering about working together. Something for Kate’s album ended up delayed by the pandemic and Fanning and Dempsey’s collaboration started to snowball. In August 2020, the duo joined up for a cover of Queen and Bowie’s Under Pressure, with both performing from their separate homes. A gap opened up in both their lives.

For Fanning, it had been a while: he hadn’t released anything since 2016’s Civil Dusk and 2017’s Brutal Dawn, a double album separated into two releases. “I was having a break, and I was giving people a break from me, as well,” he says.

He didn’t stop writing, though. “I keep saying this, and he’s getting sick of me saying it, but he writes 15 songs a day, it’s really annoying,” Dempsey says. Fanning counters: “Yeah, but only one good one a month”; Dempsey replies that his own hit rate is around two a decade.

Both agree, though, that the end result was an album neither could or would have made alone. “We kept each other away from familiar things,” Dempsey says.

There is, however, an easy familiarity. For a pair of singers, there’s little ego: they don’t get in each other’s way in conversation and the same is true of The Deluge, with the pair alternating lead vocals with ease. Sometimes, it’s hard to distinguish between them.

It was returning to the sounds of their youth that made it fun. A returning motif is saxophone, an instrument Dempsey says “needed to be rehabilitated. It became such a subject of mockery and so many internet memes … Careless Whisper and things like that.”

“How very dare you,” Fanning objects.

“Yeah, you know, it’s a wonderful instrument,” Dempsey allows. “And sometimes a song, it might have energy and it might have a groove and an upbeat vibe, but the party hasn’t truly started until the sax solo begins.”

And then there were the synthesisers that took the place of guitars for much of the early 80s. “We didn’t want pastiche or nostalgia. We just wanted that sort of sonic aesthetic, so it was like, well, what instruments were they using?” Dempsey says.

Is the collaboration sustainable? “As long as it’s fun, yeah,” Dempsey says. Fanning dials any expectations down: “We just wanted to make a record and then go on tour; that was the extent of our plans. We don’t have any super lofty ambitions.”

There are no doubts about the future of Something for Kate, who are still active. It was Dempsey’s partner and bandmate Stephanie Ashworth who pushed him to stop bantering about making a record with Fanning and to get busy making it.

As for Fanning, he won’t be drawn on the always overhanging question about the prospects of a Powderfinger reunion. “The answer is, I don’t know either,” he says. “Everyone’s busy – too many kids, too many other projects.” For now, Fanning Dempsey National Park is it.

• Fanning Dempsey National Park’s The Deluge is out now. They tour Australia in October and November