Mike Campbell certainly isn't trying to be the spirit incarnate of the late Tom Petty. But he comes by it honestly. Campbell spent 40 years by Petty's side in the Heartbreakers and was one of his chief songwriting, production and arranging partners, a "secret weapon" who was also tapped by a galaxy of greats (Stevie Nicks, Bob Dylan, Don Henley, Neil Diamond, Fleetwood Mac, etc.). And he was part of Mudcrutch, which he and Petty took West from their hometown of Gainesville, Fla., before that.

So it should be neither surprising nor a point of contention that External Combustion, the second album by Campbell's not-so-new band the Dirty Knobs (together, quietly, for nearly 20 years), is of a piece with anything from his Hall of Fame past in the Petty universe. Hell, Campbell's vocals even have the same nasal tone and biting cadence as his friend's, and there's more than a little of the same defiant, chin-out attitude in many of the 11 songs here.

But Campbell and company manage to steer the myriad familiar tropes into a territory of their own - just as the Dirty Knobs did on 2020's Wreckless Abandon. As any second album should be, External Combustion is broader and more diversified and, dare we say, truly combustible, with the same hard-rocking bite as underrated Heartbreakers releases such as You're Gonna Get It! and Let Me Up (I've Had Enough). Produced again by Campbell and George Drakoulias, External Combustion showcases Campbell's offhanded skill as an ace rock 'n' roll songwriter and arguably underrated guitarist - though the likes of "Cheap Talk," "Rat City," "Electric Gypsy" and the title track stand with, say, "Runnin' Down a Dream" in extolling Campbell's tasteful and at times scorching brand of six-string wizardry.

Solid from start to finish, External Combustion houses its share of standout moments. Ian Hunter is an inspired guest choice for the Crazy Horse pummel of "Dirty Job," as is Heartbreakers and Mudcrutch mate Benmont Tench to play piano on the double-time rockabilly "Lightning Boogie." Margo Price enriches the sweet and mournful "State of Mind" as well as the hard-hitting "Cheap Talk," both of which are fortified by carefully deployed strings and horns. The opening "Wicked Mind" is a prototypical face-melting garage rock, and Campbell gets his country on, convincingly, for the galloping "Brigitte Bardot" and "It Is Written." The latter ranks at the top of Campbell's songwriting cache, staring off with sober social commentary about climate change and the political landscape before taking an autobiographical turn to offer a touching tribute to his wife.

External Combustion assures us that the Dirty Knobs are not side-band lark but, as tragic circumstances dictate, a worthy full-time concern for Campbell and his talents. We'll take a new batch of music like this every couple of years - and even more, if he can muster.

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