Kings of Leon turn in a savage howler

For all the mysterious Southern fragility that pervades the Kings of Leon’s upcoming album, the band blew through its show at the Roxy on Saturday night with a lust and savagery that was utterly transforming.

The set was made up mostly of songs from the “Aha Shake Heartbreak” album, which will be released Feb. 22, but the Followills (three brothers and a cousin) found weighty, lead-bottomed live versions that went far past the CD’s already beyond-garage evolution.

Gone is the band once referred to as “Lynyrd Strokes” for its Southern legacy and stripped-down sound. Kings of Leon now attack like the Who.

Frontman Caleb Followill’s idiosyncratic delivery comes into its own on “Heartbreak.” The band avoids stereotypes, which could easily be applied to its Southern members who grew up the sons of a traveling revival evangelist and wanted to claim full-throttle garage rock.

On the new songs, Followill’s Tennessee drawl curls into an alien tongue, raspy and cracking, turning the word “star” on “The Bucket” to a clipped, swallowed “staw,” and then transforms the “this party is over-rated” line from “Four Kicks” into “This pahtay is ovar-red-de.”

The effect is hypnotic, the compressed sounds evoking an athletic feat, and the chopped, blunt verses on strange songs like “Razz” or “Pistol of Fire” pile image on image and refuse to coalesce.

But this nuance is obliterated live, as the songs become an explosive howl. The band has found a chiming bombast onstage. Introducing “Four Kicks,” for instance, Followill made some rare between-song banter, noting this was a “fightin’ song,” then launched the band into a roaring version that proved the original rocker could be played as raw as punk.

The Kings of Leon that made their debut album, “Youth and Young Manhood,” a few years back consisted of awkward kids who were battling labels like “Southern rock” and “pop” with equal ferocity. At the time, they were emerging from their strict upbringing to discover sex and a decadent, even profane freedom, and now they have fully emerged as angry young men with their own unique rock ‘n’ roll hybrid.

“Heartbreak” is just rotten with unflinching laments about girls with motel faces, drinking wine in the matinee and fighting at parties, but it is also about needing a new morality. These shortish, hard, sometimes brutal songs ring with authenticity, a rock sound and content that is for the Kings to own.