Caleb Followill, lead singer of Kings of Leon, says the band has a simple philosophy: It never wants to repeat itself.

Caleb Followill, lead singer of Kings of Leon, says the band has a simple philosophy: It never wants to repeat itself.

This has become especially apparent on the group's third and fourth albums, 2007's Because of the Times and the new Only by the Night.

"We try to change from album to album," Followill said in a recent phone interview. "So after three albums, you look back and there were things that you'd done that you just barely dipped your toe into the water, as opposed to really diving in. And that's something that we tried to do with every album."

Many listeners feel Kings of Leon's sound has grown by leaps and bounds on the two most recent discs - going beyond the straight-ahead Southern-rooted rock of the band's first CD, Youth and Young Manhood, to embrace a more spacious and ambitious range of music.

The band's musical arc makes sense considering its history.

The three brothers in Kings of Leon - Caleb (vocals and guitar), Nathan (drums) and Jared Followill (bass) - grew up with a father, Leon, who was a popular Pentecostal preacher. The boys traveled extensively with their father, participating in tent revivals and church services throughout the South.

In their teens the brothers began discovering rock music, and in 2000 they recruited cousin Matthew Followill (lead guitar) to form Kings of Leon. At that point, Nathan, at 21, was the group's oldest member.

Because they got a late start on their rock 'n' roll education, new discoveries are still fueling an expanding range of influences.

"We're very competitive and almost jealous," Caleb Followill said. "If we hear something that's good, it doesn't matter if our album just came out, we immediately want to start writing songs. You kind of want to be on the front end of the curve."

Because of the Times signaled a significant step forward, featuring several slow-building tracks stocked with rich vocal melodies and striking sonic treatments. Meanwhile, songs like "Charmer" and "Black Thumbnail" were among the band's most visceral rockers to date.

Some of that style carries over to Only by the Night. But the new CD is a bit harder-hitting and more immediate, while retaining the beauty of the previous album. The rockers on the new CD - like the propulsive first single, "Sex on Fire," and the massive, riff-driven "Crawl" - are even more tuneful and accessible than many of the tracks on Because of the Times.

Followill said the new songs have also had an impact on the group's live show.

"This is the first album that we really can go out there and play every song," he said. "The new songs, not only do they go over well, but they bring some length and some depth to the set that wasn't always there with our little two-minute songs.

"Some of these new songs, if we wanted to, if we were a hippie band, we could go out there and stretch to 10 or 15 minutes," he added. "We won't do that, but they really lend themselves to a big production."