Apparently not that many people care who's in a rock band, even if that band is one of the biggest in the world.

Witness Pink Floyd, which opens a four-night stand at Capital Centre tonight. Though there are still some tickets available for Wednesday and Thursday, the band figures to draw some 80,000 people to its shows with a lineup that includes longtime guitarist David Gilmour and two founding members, drummer Nick Mason and keyboardist Rick Wright.

A couple of months back, bassist Roger Waters, another founding member of the band and for 15 years its major singer and songwriter, played a single night at Capital Centre and drew less than a third of a house. Waters, who left Pink Floyd in 1983 and says its continuing to use the name without him is a sham, is suing his former bandmates.

A tempest in a teapot?

"It'll be 20 years next January that I've been helping to build the name up," says Gilmour, 43. "It's a rock 'n' roll band and if someone decides to leave it of their own free will and volition, that doesn't give that person the right to dictate the future of the people who remain within it ... The courts should decide this on a common sense basis."

The fans seem to have done that already. While Waters' "Radio K.A.O.S." album floundered on the charts, Pink Floyd's first album since 1983, the recently released "A Momentary Lapse of Reason," is already in the Top 5 and its first full-fledged tour since 1977 has been setting box-office records at many stops.

Which doesn't surprise Gilmour.

"I didn't have any doubts that we would sell out some shows, but the speed and quantity of tickets in some places was quite amazing," he says. That few people seemed to know who Waters was, and that many people seemed not to care who's actually in Pink Floyd, doesn't surprise him, either.

"People in journalism and radio and real die-hard fans of rock music are a very tiny minority," he says. "I think there's a vast bed of people out there right across America and the world who haven't a clue as to who Pink Floyd is or that there was someone called Sting in the Police or that there's someone called Bono in U2.

"I don't know that it's either good or bad," he adds. "In one way, maybe they ought to learn a little bit more about what they're buying. On the other hand, maybe they bought Pink Floyd records before and liked them and nothing else matters."

This is the first extended Pink Floyd tour since the "Animals" tour in 1977 and it continues the band's tradition of grandiose and spectacular shows filled with lasers, hydraulic stage effects, film clips, state-of-the-art lighting and sound systems and a few extras like the plane flying through the audience and the huge inflatable pigs.

"We like to keep up traditions, you know," Gilmour laughs. "It's quite big, lots of big things, big things that fly around, things that make noises, the usual rubbish. We considered an inflatable Roger Waters but couldn't get one ugly enough." The show will mix new material with Floyd classics.

If there's a certain tension attendant to mentions of Waters, that's to be expected. After all, it was Waters who didn't like to go on the road (the band's previous tour was a four-city "Wall" tour on which they lost millions because of the elaborate staging). And it was Waters who tended to disregard democratic principles.

"I didn't feel a particular need to be the leader," Gilmour says. "Roger used to insist on it: 'I want to be called the leader.' After years of saying 'Don't be silly, let's just get on with it, make records and do the things we do,' we said, 'Oh, call yourself the {expletive} leader if that makes you happy.' "

It's true that Waters "came in with more lyric ideas and more musical ideas than anyone else," Gilmour concedes. "He worked harder." Yet he adds that "I don't think most of the music he writes is that great ... Pink Floyd is and always has been about combining music, sound and atmosphere with words in such a way that the whole thing takes off. The whole thing doesn't take off on just the lyrics alone. In my view, most of the best musical moments did not come from Roger."

For years, Gilmour insists, "there was a great spirit of compromise within the group ... If someone couldn't get enough of his vision on the table to convince the rest of us, it would be dropped. 'The Wall' album, which started off unlistenable and turned into a great piece, was the last album with this spirit of compromise." It was "vastly superior," Gilmour adds, to Waters' subsequent work.

In fact, the last Waters-logged album, "The Final Cut," was advertised as a requiem "by Roger Waters featuring Pink Floyd." Waters "became totally impossible to deal with," says Gilmour, noting that some of the difficulties arose because Waters tried to revive songs rejected from "The Wall." Eventually, he began treating his bandmates as hired studio guns.

"He said the only way he'd ever consider doing another Pink Floyd album was on that basis ... I admit freely that my ego could not take that, but my musical sense also tells me that it wouldn't work anyway." So in 1983, Roger Waters left one of the biggest bands in the world. Apparently, no one noticed.

Ironically, some of the same issues had come up in 1967, when the band's original singer, songwriter, guitarist and guiding light, Syd Barrett, left the psychedelic band for the psychiatric ward. That's when Gilmour stepped in as guitarist, and when Waters began to emerge. There's still a cadre of hard-core fans who insist Pink Floyd should have dropped the name 20 years ago.

"People like a legend," Gilmour notes. "Syd was great, but Syd's ambition was to get on hit radio."

Although that never happened to him, it did happen for the band in 1973, when it released "Dark Side of the Moon," a record that just entered its 700th week on the Billboard album charts. Like Joe DiMaggio's hitting streak, that's a record no one's likely to touch for a long time.

Why the sustained fascination with "Dark Side"? "It's inexplicable to me," Gilmour says. "It's a very good record and I'm very fond of it and proud of it, but I must confess I can't put my finger on what separates it out from the other great records of all time."

The album's success forced a stylistic change and eventually magnified the band's internal disputes. "There were problems that came from the scale, the size of how big we became, and it did change the music we did," Gilmour concedes. "Before we'd had a very reverent audience -- you could hear a pin drop and when we'd do long, quite meandering sections, they'd just sit there. After the success we'd get a bunch of guys down in the front yelling 'Play "Money" ' ... all the way through the quiet sections. Pretty soon you give up on it."

Pink Floyd didn't give up completely, of course, and went on to make five more albums that sold some 60 million copies. Rick Wright left the band in the early '80s, rejoining halfway through the recording of "A Momentary Lapse of Reason." The album sounds like typical Floyd, though perhaps less sinister. There are still plenty of surreal lyrics and spacey guitar-drenched mood pieces. Gilmour wrote, or cowrote, all of the songs.

"The new album's a learning curve for me to take over the responsibility that way," he says. "It's strange after 20 years to say there's something new about making a Pink Floyd record. And I still think there's further to go.