Rumors of a Fleetwood Mac reunion are indeed true, and the band taped private concerts Thursday and Friday to be aired on MTV in August. If all proceeds as planned, the shows, the first since 1982 by what's considered the band's definitive lineup, will mark the beginning of a large-scale comeback that will include an album and fall tour.

Though guitarist Lindsey Buckingham, drummer Mick Fleetwood, bassist John McVie, keyboardist Christine McVie and singer Stevie Nicks enjoyed a multi-platinum run that began with 1975's "Fleetwood Mac" and peaked with the 14-million-selling "Rumours" in 1977, personality conflicts and drug abuse eventually took their toll on the band. Buckingham decided to go his own way in 1987, Christine McVie and Nicks split in 1992, and subsequent Fleetwood Mac efforts resulted only in cheapening the group's brand name. Mick Fleetwood and John McVie soldiered on touring increasingly smaller venues, at one point stooping to a package tour of oldies acts that included Pat Benatar.

Thus, the proposed reunion was originally met with cynicism.

After all, Fleetwood Mac circa 1997 is a band with five separate dressing rooms, five separate lawyers and five separate managers. Couple that with the inevitable cash flow problems that face pop stars over age 40, and the reasons behind the members' sudden affection for one another seem all too obvious.

Maybe so, but those in the industry don't seem to mind. Anticipating great demand to see the group, concert promoters will guarantee it $400,000 per show when it begins a worldwide arena tour in September. A live album culled from the MTV tapings will hit stores around the same time, and retailers are reportedly happy it's coming.

Based on those numbers, Fleetwood Mac appears capable of grossing about half the amount earned by the reunited Eagles, whose comeback was estimated by the Los Angeles Times to have earned $500 million from concert revenues, album sales and merchandising from 1994 to 1996 .

Still, numbers alone can't generate the kind of crowd enthusiasm that followed the tapings. Given the well-crafted new songs tested at the show and the passionate performance by Buckingham in particular, indications are strong that a new edition of the band might return to commercial success with a promotion and marketing boost from Reprise Records.

Even without that boost, the band is a powerful draw: Courtney Love, Brian Wilson, Cindy Crawford, Winona Ryder and various industry luminaries dotted the house at Warner Bros. Studios in Burbank over the two nights of taping.

One of the shows' highlights was an appearance by the 77-member University of Southern California marching band, which backed Mac on "Tusk" and "Don't Stop" at the end of the show. Although all 22 songs performed at the tapings may not make it into the MTV program, it's likely that four new songs -- "Temporary One" by Christine McVie, "Bleed to Love Her" and "My Little Demon" by Buckingham, and "Sweet Girl'' by Nicks -- will air, given the promotional nature of the performances.

BRUCE HARING