MAYER - Still waiting for the world to change.

After two blockbuster albums - 2001's Room for Squares and 2004's Heavier Things - singer-songwriter John Mayer dialed things back by releasing an album and touring with a blues-oriented group he dubbed the John Mayer Trio. Two years ago, he brought the side project to the House of Blues here for a sold-out show. But now that that's out of his system, Mayer is back on the singer-songwriter tip and returned last year with Continuum, an album that combines the approach of his other solo albums with the blues tendencies he showed on 2005's Try! The John Mayer Trio Live in Concert. And even though he hates the word "evolution," that's what stands out about Continuum.

"Continuum is the result of the trio and of my listening to different music and growing older," he explains. "It's a really compact album and very, very dense. That's because I had a lot of time. I'm a phase-shifter. I'm constantly changing shape. The album's got a lot of growth, not just compared to the work I've done before. It has a lot of growth inside the record itself. I hear songs I wrote in 2004 and songs I wrote four months ago. Through all the shifts that I go through, I was able to find out what I am always for 12 songs."

Initially, Mayer was working the Atlanta club circuit when he self-released Inside Wants Out in 1999. He soon caught the attention of Columbia Records, which signed the boyish-looking singer for Room for Squares which he successfully followed up with Heavier Things.

"I'm really happy I've gotten to the third record," he says. "I see making records as a way in which you have to earn the next one. Heavier Things has a lot of great moments on it. I remember making that under no one else's pressure but my own. I remember being kind of frantic for Room for Squares and after "Daughters,' I don't know if I expected to be recognized for anything like that. To be awarded for anything I did on that record meant more. I won two Grammys, and at that point I couldn't see anything else coming. I realized I had enough of the same notes being played."

Heavier Things established him as a singer-songwriter who bridged the gap between the jam-oriented style of Dave Matthews and the more straightforward and mature approach of someone like Sting.

"I felt like by the end of Heavier Things, I had the perfect amount of what that all was," he says. "I didn't have too much of it, but I would have had too much of that if I had gone straight into another record like that. It was the perfect time to disengage from what I had done thus far. That's where the trio comes in. I was 27 at the time when I looked around and said, "This is neat, or beyond neat. But what else is going to get me to the next place I want to be as an artist?' And that was the trio."

The trio experience has carried over into Continuum, an album that shows off his guitar playing a little more. Its catchy single, "Waiting on the World to Change," also finds Mayer making a political statement of sorts. While it can't be called partisan, it does suggest the guy doesn't have much respect for apathy.

"It is a political song," he says. "Absolutely. I would be lying to you if I said it wasn't. What's different about the song is that what political means now is completely different. Where do politics end and lifestyle begin? War would be political, but it feels like weather. It's something we know is going on. It's not like I'm singing about writing to congressmen. I'm writing about politics in as much as an artist can write about the emotional qualities of anything. I'm not seeking to change anybody's mind."

For a guy who initially intended to play the club circuit in relative anonymity, Mayer has adjusted well to life in the spotlight where even his private life (he's been linked to singer/actress Jessica Simpson) is scrutinized.

"Actually, I feel like the same guy," he says. "I feel like the same guy I was when I was 9. I'm a little more articulate - I mean a little more articulate - and a little more intelligent. My life feels like the same day, split into a bunch of little days. That's how aging happens and you wake up one day and you're 40. That's the way it's going to happen to me. I'm still trying to do the same thing. All songwriters are. We're all trying to write the perfect song."