Undated (AP) _ The year's hottest concert rumor featured the Beatles, who haven't performed in public for 25 years. Two of this summer's biggest tours will star the Rolling Stones and Pink Floyd. And there's persistent talk of a Woodstock reunion.

It's almost enough to make the traditionally staid Grammys seem hip.

The music industry gathers in New York City this Tuesday for the 36th annual Grammy Awards. Whitney Houston, Billy Joel, Sting and Neil Young are the best bets to be big winners.

The ceremony comes during a time of unease for popular music. There's no shortage of talented new artists, but the way the industry works has many experts worried that few musicians of today will be remembered like rock's first generation.

Just as rock 'n' roll has become old enough to acquire a real sense of history, it's in danger of collapsing under the weight of it.

Restrictive radio formats, a preoccupation with the past and a lack of patience for building careers are all hurdles for musicians who hope to stay around for awhile.

''I think there are artists out there who have the potential for possessing staying power, but I don't know that the marketplace is encouraging that,'' said producer Don Was, best known for steering Bonnie Raitt to multiplatinum status.

Who is leading the way in today's music world?

Michael Jackson's career is in tatters, although sister Janet has picked up the slack somewhat. The stars of Pearl Jam and Nirvana - Eddie Vedder and Kurt Cobain - seem singularly uncomfortable with the burdens of fame. Madonna's recent projects flopped. U2 is poised for an extended vacation. Prince even ditched his name.

Billboard's top albums chart reflects the current state of flux. John Michael Montgomery, Toni Braxton and Alice in Chains have all topped the chart during the last month.

Each of those artists has a following, but chances are the fans of one know nothing about the other two.

If anything, radio station formats are getting tighter and are splintering off in new directions. One trendy new format: punk oldies, for fans nostalgic about alternative rock of the late 1970s and early '80s.

Bob Irwin, an archivist who specializes in reissuing old music on CDs, remembers when radio stations used to open doors to him.

''People who were listening to Herman's Hermits were also listening to the Byrds and were also listening to Otis Redding,'' he said. ''That doesn't happen much anymore.''

It was only five years ago when Sony Music directed Irwin and two others to start exploring the corporation's huge back catalog of music. Now Sony Legacy is one of the company's most active outlets, with hundreds of projects in the pipeline, he said.

Irwin also has his own label, Sundazed, which specializes in reissues of '60s rockers such as the Turtles.

''I hate to be a doom prophet about current music,'' he said. ''But the scenes are so fragmented these days, that buying back catalogs seems to be a common denominator among music fans.''

Concert stages seem like a live equivalent to CD reissues. Veteran musicians - even many who haven't had a hit record in years - are consistently among the top draws.

''If you look at where the big numbers are coming from, there aren't a lot of new acts that are in there,'' said Gary Bongiovanni, editor of the concert industry magazine Pollstar.

Only Garth Brooks, a country star who pays homage to '70s rock 'n' roll, can qualify as a ''new'' artist among Pollstar's top 10 moneymakers last year. The list is littered with musicians who came of age during the '60s and '70s: the Grateful Dead, Rod Stewart, Paul McCartney, Jimmy Buffett and Billy Joel.

Don't expect anything different this year. In addition to the Stones and Pink Floyd, concert stages will see reunited oldies such as Traffic and Elvis Costello and the Attractions this year, and rumors of an Eagles reunion haven't died.

Pearl Jam and Lenny Kravitz show the most potential among new acts to develop as consistent concert draws, Bongiovanni said.

The letters page of the most recent issue of Rolling Stone contains mocking letters questioning whether two of today's biggest stars - Nirvana and Snoop Doggy Dogg - will be remembered years from now.

That's a sign of what is a real worry among music business insiders: the ability of artists to build careers.

Few record companies have been known as nurturers, but the pressure for a quick payoff is more intense now than ever, said veteran music manager Ronald Weisner, who counts John Mellencamp, Tevin Campbell and Steve Winwood among his clients.

''Everyone is looking for this instant, instant response, and they don't give you the opportunity to allow the public to get into anything,'' he said.

Producer Was is quick to cite his own band, Was (Not Was), as a casualty of that line of thinking.

The first Was (Not Was) album a decade ago was defiantly esoteric, with guest vocals by Mel Torme and Ozzy Osbourne. But Was said he was pressured by his record company to come up with hits.

''We were constantly encouraged to change what we were doing so we could get on the radio,'' he said. ''We were successful at that. We had a couple of Top 10 singles around the world, which proceeded to - in the long range - alienate the audience that might have really stayed with us based on what we were really about.''

Was, busy producing the Rolling Stones' new album, is taking matters into his own hands. Frustrated by the lack of commercial response to some of his projects, such as last year's Willie Nelson release, he's starting his own record company.

And guess who this 41-year-old producer is turning to?

That's right, the old folks. His first signings are Beach Boys leader Brian Wilson, actor and songwriter Kris Kristofferson and ex-Rascal Felix Cavaliere.

''Age gives these artists a depth of experience that 19-year-olds couldn't possibly write about,'' Was said, ''and therefore makes them more interesting.''