"We are going into the unknown – I don't know what's going to happen," Green Day singer-guitarist Billie Joe Armstrong admitted during a break in a mixing session, at a studio in Tarzana, California, for his band's forthcoming daredevil release: three separate albums, Uno!, Dos! and Tré!, to be issued by Warner Bros. two months apart this fall and winter.

"It's exciting and nerve-wracking," Armstrong went on. "But it's more exciting," he quickly noted with a grin, "than anything else."

That day, Armstrong, bassist Mike Dirnt and drummer Tré Cool were working on songs from Uno! – coming out on September 25th – with longtime co-producer Rob Cavallo. Everyone, including Cavallo, sat down for separate interviews for an exclusive story in the new issue of Rolling Stone, on newsstands Friday, about the three records' strange birth and Green Day's commercial gamble. But Armstrong, the group's main songwriter, spoke for more than an hour, going into detail about the music, specific songs and the charge he still gets from risk.

"When I signed that major-label contract when I was 20 years old," he noted at one point, "I did it because I wanted to play music for the rest of my life. That's every 20-year-old's dream – to do whatever the hell you want.

"This," Armstrong said of Uno!, Dos! and Tré!, "is just a crazy idea that happens to be working really well."

What did you think Green Day needed to do next, after American Idiot and 21st Century Breakdown? You couldn't do a third punk opera in a row.
People ask me all the time. Even my son asked me, "Dad, would you ever go back to playing songs like from [1994's] Dookie and [1992's] Kerplunk?" I love those records. I love the punk stuff I grew up on. But there are so many bands who make the mistake – "We're going back, old-school." Well, that's all you're doing. You already did it. So we're changing the guitar sound. We're not going with the big Marshall-amp thing. We wanted something punchier, more power pop – somewhere between AC/DC and the early Beatles.

There is a different density, from the operas, in the new mixes I've heard. There are not a lot of parts in there, but what goes on in the songs has dimension and thrust.
The last two records were studio albums. This one – we started rehearsing every day, constructing these songs together. It felt like we were all in a room jamming – everyone in the mix, throwing out ideas. If you listen to it, it feels grand. But it also feels like a garage band.

When did you realize you had three albums' worth of solid new songs instead of just one?
The songs just kept coming, kept coming. I'd go, "Maybe a double album? No, that's too much nowadays." Then more songs kept coming. And one day, I sprung it on the others: "Instead of Van Halen I, II and III, what if it's Green Day I, II and III and we all have our faces on each cover?"

Like the KISS solo albums.
I've already heard that one. [Laughs] The last record got so serious. We wanted to make things more fun.

One song on Dos!, "Fuck Time," is something you mentioned to me back when the theatrical version of American Idiot was getting started on Broadway.
A guy in the cast, Theo Stockman, started calling himself the King of Fuck. Then it got into a thing where everytime they got ready for a show, the cast members got in a circle, put their hands in the middle and went, "One, two, three, it's fuck time!" I just wrote the song. We did it as Foxboro Hot Tubs at a club in New York, Don Hill's, because we knew some of the cast members would be there. We ended up playing it ten times in a row.

We thought it would stay a Foxboro Hot Tubs song. But the more we played it, we thought, "This is pretty good. Why should we give it to our alterego?"

There is a song on Uno! – "Kill the DJ" – that is the closest thing you've done to a straight-up dance song, with power-drill guitars. It's a mix of thump and noise that recalls the Clash's work with early hip-hop beats on [1980's] Sandinista!
Mike asked me to write a song with a four-on-the-floor rhythm. I'd never done it before. It's kind of like Sandinista!, Ian Dury's "Sex & Drugs & Rock & Roll" and the Tom Tom Club song, "Genius of Love." We were trying to figure out how to make dance music without turning into a dance band.

Who's the DJ you want to kill?
It's about static and noise.

People on TV and radio, talking endlessly about themselves?
Yeah – and all of the things inbetween. Like this government cannot, will not, agree with itself. They refuse to make it work. Right, left – it doesn't matter. It blows your mind and pisses you off. It's a song about being drunk, going through this chaos, feeling fucked up and all you want to do is get more drunk: "I don't even want to know about it anymore."

"99 Revolutions" on Tré! has a lot of Occupy-protest references. Did you go to the Occupy protests in your town, Oakland?
Um, yes and no.

Which is it?
We wanted to be part of it in some way. I thought it was about working people and where we come from. But Oakland got really complicated when the anarchists started coming in. I'm not into that – smashing the windows in a small business.

Are you a 99 or 1 percenter?
I feel like a 99, but technically I'm a 1. You know, it was an easy song to write. I know that's where I come from – the 99 – even though I can afford for my kids to go to a good college. It's interesting: Cops are 99 percenters. Firemen are 99 percenters. That's where the anarchists are confused. This is much broader than you think it is.

Do these three new albums count as one under your record contract – or three?
One. Believe me, we asked. [Laughs] There was no getting around that. That was fine. The record company have been great about it, just stoked. People get so caught up in not trying to do something new and creative: "Let's just put out an EP." We said, "Let's do the exact opposite, something dangerous and fun."