No one could have known it at the time, but with albums from fellow alternative metal acts Karnivool and The Butterfly Effect to follow in quick succession, Cog turned out to be the catalyst that began Australia's progressive music explosion, which would surge in popularity in the years that followed.

Two and a half years later - after debuting at #1 on the AIR chart, #19 on the ARIA chart and conquering the local touring scene (by now populated with the likes of Dead Letter Circus, Mammal and Sleep Parade, all of whom owe Cog a huge debt of gratitude) - returning to Weed and Massy to record The New Normal's massively-anticipated follow-up must have seemed like a great idea at the time.

But after running out of money, falling out with Massy and having to stick out the final two weeks of the session on their own, they must have wondered how it all went wrong.

Luckily they pulled through in the end, and the resulting album Sharing Space is a deep and confronting release, befitting the trials that Cog went through in creating it.

While the lyrics show a move towards the more direct and hard-hitting, there is a definite shift away from the driving riffery that underpinned The New Normal, as bassist Luke Gower explains. Liberal use of keyboards, strings, vocal effects and harmonies make for a far more, dare I say it, progressive album, at least musically.

"I think it was a bit of a natural progression for us, we love experimenting," says Gower. "[But] it's not like we set out to say 'oh in this song we want to put down three different keyboards' or anything like that. It could be, you know, you're tracking a song and making a cup of coffee in between doing something and you see an instrument sitting on a shelf that you've never seen before, so you go over and flick it on and fuck around with it for a while, and it's like 'fuck, that might actually work in that song'.

"We're very open to experimentation in terms of instruments and we all write on each other's instruments as well so there's a huge diversity of what we can come up with. All egos aside, it's just all about the song and what's best for that. I mean we put some things down and they don't work so we piss them off, but that's just the way we work."

Lyrically filled with overt political statements such as "I don't listen at all to the Government / the Government has gotta go", and written mostly in the lead-up to Australia's 2007 federal election, you'd be excused for thinking that the Cog trio had set out to write a protest album. But as it turns out they were actually almost completely unaware of the situation back home for the 10 months they were stuck in the studio.

"I suppose to the outsider, they would be like 'yeah they're talking about John Howard' ... but we didn't set out specifically to write about the situation that was going on in Australia. To tell you the truth we didn't really watch any TV and we weren't getting any newspapers, the only form of news we had was when you log in to Hotmail, and you know what that kind of news is like, they're more worried about Megan Gale and fucking 'the actor from Home and Away's been caught on the beach wearing a new bikini', you know."

Regardless of the lyrics' inspiration - the bushy-browed Howard, the bushy-tailed Gale, or neither - the candidness on Sharing Space may come as a bit of a surprise to existing fans used to Cog's extensive use of metaphor and allegory. That, though, was a conscious decision.

"(Politics is) something that we feel strongly about, it's hard not to with the things that are going on these days I think. I wanted to try and target specific issues, whether it be political or whatever the song was going to be about, I really wanted to try and hone in a bit more so as not to be as sparse as the last album."

Given that background, Sharing Space is a title as appropriate as it is poetic. Exploring themes such as time away from loved ones, fear as a tool of government to quell dissent, and the more obvious theme of political change, the one idea holding the album together is that we're all "sharing space", and that with the right to individuality comes a responsibility to ensure you're doing the right thing by your fellow man.

"Instead of saying 'thanks for having me' or 'thanks for hanging out', [Weed locals said] 'thanks for sharing space' ... and we all thought that was a fitting title for the album. It's applicable to the time we're living in at the moment on all sorts of levels, it can work on a macro or a micro level I think."

Cog will be sharing space with Jakob, Kora, Melodyssey and Sleep Parade on their "Sharing Space" tour, taking in five states throughout May and June.

Sharing Space is out now through Difrn't Music.