THE POWER OF FOUR HARMONY COMES BACK TO THE WORLD OF CSNY.

Byline: Fred Shuster Music Writer

It seemed like ``Deja Vu'' all over again.

After releasing just two studio albums in 26 years, David Crosby, Stephen Stills, Graham Nash and Neil Young - CSNY, the acronym goes - found themselves in the same room, playing tunes and harmonizing together as if all those years when they had been apart didn't matter.

The current CSNY reunion tour had its roots in that rehearsal room where Crosby, Stills and Nash were simply singing for themselves last year after coming to the conclusion they would have to shell out their own cash to record before a major label would be interested in marketing something new from the trio.

At some point during those sessions, Young dropped by.

``He liked that we were paying for it ourselves, and he liked the music coming out of the speakers,'' said Nash, who had quit the British pop band the Hollies in 1968 to help form CSNY in Los Angeles. ``At first Neil wanted to play on one of Stephen's songs, but we just kept going. We realized we had a CSNY record and not just one where Neil was guesting. So we decided to take it on the road.''

Taking it on the road meant the first concert tour by the legendary quartet in more than 25 years. The last time CSNY hit the highway, Richard Nixon was president and the Eagles' ``Best of My Love'' topped the charts.

Memories go back a long time - CSNY's second live appearance was in front of half a million people at the Woodstock festival in August 1969.

Today, the group has a new album to sell - the disappointing ``Looking Forward'' (Reprise) - and the 33-date, three-month tour (which comes to Staples Center on Saturday) is getting mixed reviews. Most observers agree that when the band's golden harmonies click on stage, nothing compares. The problem is, the new material doesn't come close to winners such as Young's ``Cinnamon Girl'' and ``Southern Man'' or Crosby's ``Guinnevere.''

For their part, the band members are talking as if there's more at stake than merely ticket sales.

``It's an archeological dig,'' Young said. ``We're looking for ourselves, and we're coming pretty close.''

It didn't take much excavating for the media to come up with a bit of spice to add to news of the tour after the story broke that Crosby was the sperm donor for rocker Melissa Etheridge and her partner Julie Cypher's two young children.

Crosby was the biological father of the couple's 3-year-old daughter and 1-year-old son, borne by filmmaker Julie Cypher, by means of artificial insemination.

``There's been a lot of razzing and a lot of very, very funny lines,'' Crosby, 58, has said.

Rehearsals for the tour, dubbed CSNY2000, took place at the Forum, where the band worked out about 50 numbers so the three-hour, 30-song program, including electric and acoustic segments, can vary each night. The backing band includes bassist Donald ``Duck'' Dunn of Booker T. & the MG's fame and well-known session drummer Jim Keltner.

``Things have been going unbelievably well,'' Nash, 57, said. ``It's thrilling to stand in front of such love. We've always tried to do the best we could. When we first started, we didn't sit down and say, 'Boy, this is going to last forever!' That first time we sang together was an amazing feeling. When we heard that vocal blend, it was surprising how different it sounded.

``We have no particular claim to any series of notes. Anyone can sing them, but nobody sounds like us.''

Those close, high harmonies sold millions of albums and influenced legions of soft-rock groups throughout the `70s. But the personalities of Crosby, Stills, Nash and Young - all of whom play guitar, sing and write their own songs - were not as mellow as their tunes. The band split up and re-formed many times through the years.

There were many false starts at reunions after the final 1974 outing ended at London's Wembley Stadium. Young joined CSN for a lackluster performance at Live Aid in 1985; Crosby went to prison after a long series of run-ins with the law due to drug use; and after recording the 1988 quartet album, ``American Dream,'' Young refused to tour with his bandmates.

Although the trio's next record, ``CSN,'' failed to make the Top 100, the group maintained a large, loyal following, and concerts featuring various permutations of the original quartet continued to draw fans.

Of the four original members, however, flannel-clad grunge-guitar god Young has enjoyed the most serious rock stardom, and his solo concerts are multigenerational affairs.

Yet, the band members seem clearly delighted to be together on stage again - at least this early in the current trek.

``It's still fun,'' said Nash, who recently broke his legs in a boating accident in the waters off his Hawaiian home. ``The new songs are going down as well as the old songs. And that's a surprise. We're feeling optimistic about the future. Everybody has really improved as musicians, and we're all actually listening to each other. We haven't done the same song the same way twice in a row.''

Nash, whose leg casts came off a couple of weeks ago, takes a dim view of the state of the music industry, where consolidations and mergers have shrunk the number of major labels to four.

``It used to be the record companies cared about their artists and cared enough to nurture them through an album and two or three singles,'' Nash said. ``And if the first single didn't do anything, they'd plug the hell out of the other ones. Today, it's like throwing mud at the wall. The labels today are run by accountants. But the more time people spend on their computers, you won't need the traditional methods of distribution and media. And that's going to be a good thing for everybody.''

THE FACTS

--Who: Crosby, Stills, Nash & Young.

--Where: Staples Center, 865 S. Figueroa St., Los Angeles.

--When: 8 p.m. Saturday.

--Tickets: $30.50 to $201.

--Information: [phone].2

CAPTION(S):

3 photos

Photo: (1 -- cover -- color) Still CSNY after all these years

(2) Stephen Stills, left, Graham Nash, David Crosby and Neil Young are back on the road promoting a new album and singing the songs they made famous over two decades ago.

(3) Nash, left, Young, Stills and Crosby, shown here back in the day, have reunited as CSNY a number of times. The quartet performs Saturday at the Staples Center.