"One is that you want to relive your rock star youth," said Plymale, a music producer and former member of the Pressure Boys, one of Chapel Hill's most prominent bands in the 1980s. "Two is that you have a bunch of new songs and want to get back together to make a new album. And three is that you know a reunion tour can sell out some places and you can make some money."

The Pressure Boys broke up in 1989. Although the possibility of a reunion occasionally arose in the years afterward, none of those reasons appealed to them, and the idea never caught fire.

But it turns out there's a fourth reason to get back together.

"Do it for a cause," Plymale said. "We never were drawn to the idea of doing it just for the sake of the band -- I mean, we were this crazy, kooky band 20 years ago, and how do you live up to that? But this idea takes the spotlight off the band and puts it onto the cause. It seems like a more worthy reason to do it."

The P-Boys, as their fans called them back in the day, are reuniting after 20 years for two shows, and a new CD featuring 18 remastered tunes, at the Cat's Cradle this weekend, with all proceeds benefiting the Cystic Fibrosis Foundation. The reunited band will feature Plymale, Bryon Settle, Greg Stafford, Rob Ladd, Jack Campbell, and Je Widenhouse.

The Pressure Boys reunion is the second project done by Songs for Sixty Five Roses, an initiative Plymale founded after his daughter Allie was diagnosed with CF in 2004. The first was a concert and CD called "Songs For Sixty Five Roses" (which is how some children pronounce "cystic fibrosis"), that featured an array of top North Carolina artists performing songs by other North Carolina artists. The concert and CD sales thus far have raised more than $30,000 for CF research.

This weekend's Pressure Boys shows and the new CD should make a nice dent, too. If you want to go Friday and don't yet have a ticket, forget about it; that was originally going to be the only show, but it sold out in a hurry and the band added a second show. Tickets to Saturday's show are $16 in advance, $20 at the door. Call 967-9053 or see www.catscradle.com.

Also reuniting for the show is the legendary Winston-Salem band Sneakers, featuring Mitch Easter, Chris Stamey, and Will Rigby. Absolutely the Maybes will open.

Allie, incidentally, is doing great, Plymale said. CF impairs lung functioning and can lead to a whole host of serious respiratory and digestive problems, but Plymale said Allie has responded well to her treatment program.

"The medical things are doing what they're supposed to do, and she's in great shape," he said.

Back in the '80s, the music of the Pressure Boys -- a quirky, infectious highly caffeinated blend of ska, reggae, funk and most other musical categories you can think of -- was a dominant part of the Chapel Hill soundtrack.

Launched in 1981 by a quartet of Chapel Hill High School students and two CHHS grads, the P-Boys grew into one of the best and best-known bands in a place and a time that was full of great bands. A huge favorite in local clubs, they released a couple of EPs and one LP, "Krandlebranum Monumentus," and opened for acts including R.E.M., Billy Idol and Oingo Boingo.

After eight years of almost ceaseless playing, the Boys were no longer boys, and in 1989 they called it quits.

"We just ran our course," Plymale said. "We all grew from high school students into young adults during the course of the band. We had seven and a half years. That's a good run."

Two of the P-Boys, drummer Ladd and bass player Campbell, now live in California. They made the flight back here in January to do a little rehearsing with the rest of the band.

"We ran through 20 or 25 songs a handful of times," Plymale said. "I think we were all pleasantly surprised at how much fun it was."

In addition to the reunion show, Songs For Sixty Five Roses will release "The Pressure Boys: The Incomplete Recordings," featuring 18 tracks from the band's three recordings from the 1980s. The original records have been out of print for some time and had never been remastered until now.

The CDs will be available at the shows and through online distribution sites including CD Baby and iTunes. All proceeds from sales of the CD, as well as from the concert, will go to the Cystic Fibrosis Foundation. For information and links, see www.pressureboys.com.

"We're excited about it," Plymale said. "We're looking forward to playing together, and the best thing about it is that every penny will go to the foundation."