Isaac, Taylor and Zac Hanson--20, 18 and 15, respectively--were invited to attend Copeland's annual "Songwriters Boot Camp" in May at a castle he owns in the South of France, and the results will be evident on the trio's next album, currently in production and tentatively due in the spring.

It's all part of their ongoing move to graduate from associations with the teen-pop wave as they work on their third album.

Where the group's evanescent 1997 hit "MMMBop" made them the object of screaming-girl affections and presaged the arrival of the Backstreet Boys, 'N Sync, Britney Spears, et al., Hanson has since distanced itself from that world. Its last album, 2000's "This Time Around," focused on straight-ahead pop-rock, and the group associated with such earthy figures as the Grateful Dead's Bob Weir and Blues Traveler frontman John Popper.

At Copeland's castle, the three found themselves in a class of about two dozen musicians, including Ed Robertson of Barenaked Ladies, Donny Brown of the Verve Pipe, producer Mark Hudson (who had worked with Hanson before) and Carole King, whose own journey from early-'60s Brill Building popsmith to a leading '70s singer-songwriter resonated with the Hanson brothers.

"I wasn't going to walk up to [King] and say, 'Remember when you were teen pop?"' says Taylor. "But it was very cool. She's an incredible talent. We all sat around and played things from the [Beatles'] 'White Album' to Crosby, Stills and Nash songs, talking until 2 or 3 in the morning."

More important, they wrote songs. The students were divided into groups of three, each assigned to write a new song and record it in just three hours. Several of the castle collaborations are likely to wind up on Hanson's new album.

Since the French stint in May, the brothers have also been writing a lot with power-pop veteran Matthew Sweet and on their own and are about halfway through making the new album. As far as their current tastes are concerned, Taylor names influential '70s underground power-pop band Big Star as a current favorite of his, while Zac has been listening to Coldplay, David Gray and Train among current releases, along with the albums of revered late English singer Nick Drake. They have no interest in reclaiming the teen-pop market, to which they don't really give much thought at all these days.

"If our entire music career was based on trying to say what we're not, that would be a bad thing," says Taylor. "The key is to focus on what we are, which is a rock 'n' roll band."