Too many people, Phil Collins says, tend to forget the genesis of a rock 'n' roll band.

Especially his own.

"They were friends first and they got together to play music," says the drummer and singer who is back as frontman for Genesis as it returns from a 15-year touring hiatus.

Reuniting after so long was no big deal, adds Collins, whose old group begins a North American tour this week. After all, the three core members taking to the road -- Collins, Tony Banks and Mike Rutherford -- have been friends for more than twice that long.

"We played at my wedding (in 1999). We played at my 50th birthday party," the 56-year-old musician noted during a recent phone interview from his home in Switzerland.

Indeed, the group even played at the 2002 wedding of Peter Gabriel, Genesis' lead singer before he left in 1975 to pursue a solo career and Collins stepped out from behind the drums to replace him. It was a move, Collins jokes, that has the band's most hardcore fans still referring to him as "the new singer."

There was talk at one point of Gabriel also joining this tour, along with guitarist Steve Hackett, who left the band in 1977. That would have reintroduced audiences to the full quintet that rose to fame in the early 1970s with albums like "Selling England by the Pound" and "The Lamb Lies Down on Broadway."

"But Pete still had to finish his (own) album and he still didn't know if he really wanted to do it," Collins said, recalling a November 2004 meeting the five called to discuss the matter.

"Steve said he was in if we did do it," he added, but it turned out the guitarist wasn't as interested if Gabriel wasn't coming along.

Finally, after a meeting that lasted so long Collins said it began "to feel a bit like watching paint dry," Hackett and Gabriel decided to go home. And the other three decided to go back on the road.

"We thought, well, let's do this lineup, which in a way, for me anyway, is sort of the main group, you know, because it lasted for so much longer," Banks said in a separate phone interview.

Once they began rehearsing, he added, it was as though they had never been apart.

"It felt very natural, really," Banks said. "Almost from the word go, as soon as you started playing a song, it was like you hadn't been away."

For Collins, who last toured with Genesis in 1991 and had left the group 11 years ago, the transition was harder.

"I had to learn how to play the drums again," he said bluntly.

Although he continued to tour with his own band, he had turned more to singing and songwriting in recent years, winning an Oscar in 2000 for "You'll Be in My Heart," the hit song from the animated Disney movie "Tarzan." More recently, he did the music and lyrics for the Broadway version of the film.

Returning to the drums proved daunting during a rehearsal concert the band held a few weeks before embarking on the European leg of its reunion tour earlier this year.

"I thought, `God, it was never this difficult,"' he recalled with a laugh, adding he still can't jump quite as high as he once did during his "tambourine dance."

"But I just hadn't done it," he said of playing the complex rhythms to some of the band's earlier songs. "I had to get my stuff back.

"I got it back now," he added confidently.

Like he did in Europe, Collins will spend about a third of the band's 2 1/2-hour show on the U.S. tour behind the drums, coming out front the rest of the time to sing while veteran Genesis sideman Chester Thompson keeps the beat. The group's other veteran sideman, Daryl Stuermer, plays bass and guitar.

The band promises the same mix of familiar favorites like "Tonight Tonight Tonight" and "Hold on My Heart" that it performed on the European leg. The only new material, Collins said, will be the 20-minute, freeform "drum duet" he'll engage in with Thompson.

After the tour ends in Los Angeles in October, the group's members have no plans to record an album or go out on the road again. They say they need neither the money nor the aggravation of getting back into the cycle of constant recording and touring.

"We'll just do this, do the North American leg and just see how we feel," said Rutherford. "I think it's quite nice not making an all-encompassing master plan."

It is possible, Collins said, that the three could go into the studio, create a new Genesis album just for the creative satisfaction of it all and then never release it.

Although the band rates a notch or two below the Rolling Stones in popularity among groups of its era, its hard-to-categorize progressive pop-rock sound has never been a huge favorite of the critics. That is something that has always rankled Collins, so much so that he said, "I'm quite happy to write the songs and never put them out.

"The satisfaction comes from writing them, frankly," he added. "I love the writing. I don't necessarily love the idea of putting the album out so that everyone can beat it up."

Besides, he adds, returning to his more upbeat persona, he has many other interests these days, including working on another Broadway musical, improving his golf game, gazing out the window of his home at picturesque Mount Blanc and, most importantly, being home to help raise his 2- and 6-year-old sons.

"I know it's not rock and roll," he says, laughing at what he's just said. "But it's enough for me."