The Kills rock on, paced by Mosshart's vocals

Ah, the Look of Rock - never something to be underestimated, and certainly not when assessing the effortlessly cool, essence-of-rock-and-roll figure that front woman Alison Mosshart cut on the TLA stage Wednesday.

Although more visible in recent years as the singer in the White Stripes' Jack White's other band - not the Raconteurs but the more recent Dead Weather - the Florida-born Mosshart was back in Philly with long-standing musical compadre Jamie Hince in their duo, the Kills.

And looking great, from her tousled, long, straight black hair with eye-length bangs to her bevel-heeled black boots, perfectly complementing the slant of a monitor when she propped one foot up, bent her black-clad knee, and leaned into a classic edge-of-stage vocalist pose.

Crucially, though, the Kills have never been about style over substance or fashionable appearance over an ability to rock. Because rock they did, a drum machine pacing them as the British Hince ripped out guitar riffs 'n' strokes, imbuing his blues chops with post-punk angularity, while Mosshart prowled the stage, singing in bad-girl growls or smooth to shouty croons, her body twitching to the affecting music in unerring, soul-wired sync.

This month the duo released Blood Pressures, their fourth studio album since joining forces in 2000, and it contains more of the slightly scuzzy blues-rock-pop grit the Kills are known for.

After opening with the title track of their 2005 album, No Wow, the Kills launched into the new disc's "Future Starts Slow" for the first of eight songs from it. To start the encore set, Mosshart stood still and showed her non-rockin' range as Hince played swelling keyboards to accompany her brooding ballad "The Last Goodbye." With Mosshart sure to be caught up with another Dead Weather record and tour and Hince due to marry supermodel Kate Moss (with Mosshart as his "best man"), one hopes this wasn't their last goodbye from a Philadelphia stage as the Kills.

Earlier, Matador recording artists Cold Cave delivered a well-received opening set of dark synth-rock. Wes Eisold - previously in the punkier American Nightmare and Some Girls and coproprietor of the alluring, sadly defunct Center City bookstore Juan & Juanita's - yelped tunefully over neo-New Order beats punctuated by blasts of modern industrial noise.