LOS ANGELES — Alone in the darkness behind the outdoor stage, Brandon Flowers jumped up and down and waved his arms like a boxer preparing for a fight, and wailed "hey-yay-hey!" over and over at the top of his voice like a street-corner crazy.

In a few minutes the singer would join the other three members of the Killers for the parking-lot performance on "Jimmy Kimmel Live," part of an intensive campaign launching the band's second album, "Sam's Town."

Just his standard pre-show warmup?

"I don't know what I'm doing," he said with a laugh, as he jogged toward the stairs of the stage.

Flowers might have been joking, but that's exactly what a lot of people are thinking about the Killers as the Las Vegas-based band returns with the follow-up to its rags-to-riches debut, "Hot Fuss." Second-album time is a crucial career juncture for any pop act, and the Killers have used the occasion to unveil a radical redefinition.

Instead of the obvious — another helping of steamy, noirish scenarios set to thumping, catchy, faux-British synth-rock — "Sam's Town" is filled with guitar-based anthems that aspire to something more substantial, rooted and American.

It still has the Killers' flair for hooks, but its grand, sweeping scale proclaims that the Killers want to be a band that matters, one with a fist-in-the-air connection with its audience.

"There's that feeling you get when you're in a stadium, and U2 plays 'One,' what that means to everyone there," Flowers, 25, said. "And it doesn't have to be to that many people. You go from U2 size where they sell 35,000 every night to where Morrissey always sells 2,000 a night, but when you're there, there are moments that are just — people say it's a substitute for religion for some people. We're believers."

Flowers, a passionate music fan and a competitive, ambitious player, knows that nothing is guaranteed in rock these days.

If nothing else, "Sam's Town" fulfills two of Flowers' primary aims.

"For me, the things that were deliberate were to sing like an American, because I'm an American, and to sing about what I know about instead of fantasies," he said, sitting with bassist Mark Stoermer in a dressing room at the Hollywood studio where Kimmel's ABC show is shot.

"Fantasies are OK too, but I just felt like I wanted to make an album that people could relate to right now," he said. "I guess the American thing came from people who were talking about how English we sounded, and me actually singing with a fake accent. ... Americans are getting a bad rap right now, and we felt that everywhere that we went, whether it was Germany or France or wherever, there's a look that you get when they hear you open your mouth. ...

"It's because of the war and everything that's going on. It's understandable, but to an extent it's not fair because we're just people that were born here, and we're not ashamed of it, and I wanted to sing about growing up here and things that I know about and humanize us in a way," he said. "People don't see that, they see us like monsters."

CRITICAL POUNDING

The Killers' new sound (and the hirsute look that goes with it) might open new horizons for the band, but it's also brought it its first critical pounding. Even though the balance of the reviews has been positive, three high-profile outlets — Rolling Stone, Entertainment Weekly and The New York Times — lit into the Killers, calling the band calculated and cliched, more Bon Jovi than U2.

"The funny thing about the negative press is that it's never about the record, it's always about the way the band looks or something that Brandon said," said Rob Stevenson, the A&R executive at Island Def Jam Music Group who signed the band. "I think it's really transparent. ... I think it hurt them a lot, because those negative reviews were really personal."

"Some indie kid on a blog, we expect that," added Flowers. "But those are ones that we expected to be smarter. Like Mark was saying, they're so used to people not being good that they don't want to believe it. They just want to believe it's a rip-off.

"And it's not. ... You can't find a moment on this record that's stolen from anything. I mean, this is real music that we're writing; I think it's been so long that they're not used to it. Everybody just waits for U2 to make another album to go see a stadium show or to have something be exciting and big and smart."

RETRO SOUND

It hasn't taken the Killers very long to reach this point. The group started in 2002 when Flowers, a fan of David Bowie, Depeche Mode, the Cure, Oasis and Morrissey, among others, teamed with guitarist David Keuning. Stoermer and drummer Ronnie Vannucci completed the lineup after some other players came and went, and they got their record deal shortly after Stevenson heard their demo recording.

The Killers learned something about the demands and rewards of success when "Hot Fuss" arrived with no fanfare in June 2004 and quickly seemed to take over rock and then pop radio, fueled by Flowers' brashness and rock-star stance. Its U.S. sales are up to 3 million.

How long they'll be on the road now depends on the success of "Sam's Town." The album sold an encouraging 315,000 copies in its first week, but it's the long haul that will tell the story.

"There's lots of things that sell 10 million records two years ago and then they're gone and no one cares about," said Stoermer, 29. "We want as many people to like us as possible, but there's something about a longevity to the songs, that they could be played 10 years from now, that's what we're trying to achieve."