Give a listen

It's been eight years since Tom Petty made an album with the Heartbreakers, the esteemed band that the straw-haired rocker's been touring with since the 1970s and will back him up when they play the Wachovia Center on July 31 and Aug. 1.

In the interim between their last studio album, The Last DJ, in 2002, and the bluesy Mojo (Reprise ***), which comes out Tuesday, however, the 59-year-old Florida native has hardly been idle.

Petty has seen his stature grow as the most consistently pop-savvy of an elder generation of '60s-schooled American rockers. He's done so while touring extensively with the Heartbreakers, collaborating with director Peter Bogdanovich on the 2007 rockumentary Runnin' Down a Dream, and knocking out a dependably catchy solo album - Highway Companion (2006). In 2008 he also reunited and toured with Mudcrutch, his jammy pre-Heartbreakers '70s band.

In its leisurely pace, Mojo feels very much an outgrowth of Petty's work with Mudcrutch. It also draws heavily from British electric-blues explorers like John Mayall and Peter Green, who turn up regularly on the Sirius/XM satellite radio show Tom Petty's Buried Treasure.

That's good news for fans of the Heartbreakers, which get to stretch out beyond confining pop-song conventions. Two of the three opening cuts, "First Flash of Freedom" and "Running Man's Bible," are more than six minutes long. And while the third, "Jefferson Jericho Blues," is considerably tighter, it's a Howlin' Wolf-inspired roadhouse workout that will almost certainly turn into an extended boogie when the band gets hold of it on stage.

All that extra room means that Mike Campbell, the ace guitarist who's been Petty's right-hand man for decades, has more space to display everything in his always-tasteful, never-boring bag of tricks. Campbell is an unsung guitar hero precisely because he never aims to attract attention to himself, and his lively, well-thought-out solos and fills, like the snarling lines that brush up against Petty's distorted vocals in "Takin' My Time," always make serving the song top priority.

For all the pleasures to be had in the interplay between Petty and his five-man ensemble, though, Mojo is a moderate disappointment. It's uncharacteristically stingy when it comes to delivering the radio-ready pop hooks that have been second nature to Petty for so long.