Why has it taken, um, forever, for jazz-rock fusion masters Return to Forever to reunite?

It's been 25 years -- which is like forever in the music business -- since the classic 1970s RTF lineup of pianist Chick Corea, bassist Stanley Clarke, drummer Lenny White and guitarist Al Di Meola toured together.

It's not like they haven't thought about it. "It's been simmering there for years and years," leader Corea said recently. "When I talk to the guys, we reminisce and say, 'Let's do it again.' Last year we finally made the decision and said, 'Let's clear our schedules for next summer and do it.'"

Corea, 67, knows something about busy schedules. This year, in addition to 48 RTF concerts booked in North America and Europe, he has toured as a duo with banjo god Bela Fleck and in a jazz trio with vocalist Bobby McFerrin and drummer Jack DeJohnette.

In fact, Corea has been so busy that he set aside only two days to rehearse with Return to Forever in Austin, Texas, where the tour started May 29.

In the 1970s, RTF introduced thousands of long-haired rock fans to jazz with a new style known as jazz-rock fusion (sort of a cousin to prog rock) that crossed over to the pop charts.

In an interview before tour rehearsals, Corea spoke fondly about what each of his old bandmates brings to the mix.

"Stanley's my partner in creativity with the band," the bandleader said. "He's a wonderful composer. He cares for the overall effect of the band -- our repertoire, how the band sounds and communicates. Stanley brings a great groove and musicality to the music.

"Al is the 'singer' of the band. He's got a great way of rendering the melodies with his guitar. Over the years, he has turned into an incredible improviser. He's developed completely his own harmonic language. Of the four of us, Al comes from a different musical background; we come from a pure jazz background.

"Lenny is a lot of fun. He's a groove master. He's one of the only drummers I know who combines a varied rhythm jazz approach that he brings to rock music and the kind of beats we play in RTF. It keeps the music very improvisational."

Actually, Return to Forever started out in 1971 as a Latin-flavored acoustic group featuring Flora Purim on vocals, Airto Moreira on percussion, Joe Farrell on sax and flute as well Clarke and Corea. After Purim and Moreira left in 1973 to form their own group, Corea decided to go fusion, adding electric guitar, synthesizers and funk-rock drummer White. Di Meola, 19, jumped right out of Berklee School of Music to bring his raised-on-rock guitar to RTF.

That classic lineup made three big-selling albums, including 1975's Grammy-winning "No Mystery." But after the 1976 concept album "Romantic Warrior," Corea disbanded the group and created a new incarnation with a horn section and vocalist Gayle Moran, his wife. He pulled the plug on RTF in 1977, but reunited with Clarke, White and Di Meola for a 1983 tour.

'Dustin Hoffman of music'

The son of a jazz trumpeter, Armando Anthony Corea grew up in Boston surrounded by jazz. He began playing piano at age 4 and the drums at 8 (and discovered classical music). After short stints at Columbia University and Juillard School of Music, Corea turned pro on piano. In 1968, he replaced Herbie Hancock in Miles Davis' group, playing on the landmark albums "In a Silent Way" and "Bitches Brew."

He left in 1970 to form his own avant-garde group, Circle, before founding Return to Forever. In the '70s, he also worked on other projects, including duos with Hancock and vibraphonist Gary Burton. Since then, he has formed other groups (Elektric Band, Origin, Akoustic Band), recorded and performed classical music, standards, solo originals, Latin jazz, tributes to great jazz pianists -- you name it.

"I like to consider myself the Dustin Hoffman of music," Corea said. "I first saw him in a TV movie before he became well known. I got taken by his acting, but he played an old Englishman who was an accountant in the 1800s. So when 'The Graduate' came out, I'm expecting to see this old guy with a beard; the shock was he was this young guy, the lead guy.

"I had a little epiphany at that point and thought what the role of the actor with that kind of ability could be, to play such divergent roles."

So he takes a similar approach with his art, following his interests into different territories.

To coincide with this reunion tour, RTF has released "The Anthology," a two-disc retrospective. Corea talks about writing new material, but no recording plans have been made.

"There is an intent that we all have to keep the band going as a mothership project, to keep coming back to the project when we like to," he said. "A lot of years went by and we all realized what fun it used to be. But it's all kind of an experiment in a new unit of time."

In other words, nothing lasts forever in the music business-- except the music.

Jon Bream • 612-673-1719