Since 1995, Chan Marshall has been making music as Cat Power, a band in constant flux. Marshall is the only permanent member of this band, the only one who matters. Whether she’s enlisting members of the underground elite (see 1998’s Moon Pix, on which the Dirty Three backed her) or drifting toward the mainstream (see 2003’s You Are Free, which featured cameos by Dave Grohl and Eddie Vedder), she remains much the same. The high priestess of beautiful losers, she has perfected a form of post-rock chamber blues that sounds at once confessional and detached, spontaneous and stylized. Guided by intuition and sensibility rather than formal conventions, her songs seem more like exercises in self-hypnosis than finished compositions; like all Romantic utterances, they’re aspirational, always groping at the inexpressible. They’re not so much songs, really, as broken rhapsodies in the key of regret. The Greatest, her seventh album, finds Marshall at the storied Ardent Studios in Memphis, in the company of producer Stuart Sikes and the most unlikely supporting cast yet. For those of us who crave the carnal epiphanies of classic Hi and Stax sides, the lineup is a dream come true. Al Green’s longtime sideman Mabon “Teenie” Hodges, the genius who co-wrote “Love and Happiness” and “Take Me to the River,” plays guitar on all but two of the CD’s tracks, and his equally amazing brother Leroy “Flick” Hodges plays bass on about a third of them. Steve Potts, a member of Booker T. and the MGs, handles drum duties throughout, and various studio veterans contribute keyboards, horns, and strings. Never before has Marshall played with such brilliant backing musicians, and never before has she sounded more like herself. Although it’s tempting to call The Greatest indie-rock’s answer to Dusty in Memphis, the comparison is flawed. Everyone always knew that Dusty Springfield, despite her lack of Southern (or even American) credentials, was a soul singer; by going to Memphis, she simply apotheosized her status. Marshall, who grew up in Georgia, has always been a soulful singer, but labeling her a soul singer would be a stretch; even when she hires the most cred-laden sidemen imaginable, no one with working ears will mistake her for Ann Peebles. So instead of Chan in Memphis, she gives us Memphis in Chan, a gorgeous involution of a Southern-soul record in which she doesn’t so much inhabit the South as internalize it. Like all Cat Power’s best work, The Greatest doesn’t lend itself to paraphrase. Lyrics that fall flat on the page — “I love you and I miss you,” “I hate myself and I want to die”— are inexplicably profound when sung. Marshall’s voice, a halting contralto, is raspy but improbably pure of tone; as if to defend herself against its beauty, she swallows her consonants, stretches her vowels into long sighs. Refracted through double-tracked harmonies and borderline-goofy Raelettes-style background sass, Marshall’s voice dominates even when it’s barely decipherable. In collusion with the hymnlike piano echoes and rawboned guitar riffs, the swaggering horns and stabbing strings, the roiling bass and seasick rhythms, it knocks you out with its sucker-punch kiss and dopes you up with the pop narcotic. Near the end of “Willie,” the CD’s devastating centerpiece, she pleads, “Please don’t let me go/I’m on the same side as you/I’m just a little bit behind.” Somewhere between an apology and a promise, the lines themselves seem to stagger and list, a cunning enactment of Marshall’s signature phrasing, her compulsive use of 2/4 syncopation, her resistance to everything outside the eternal lyrical present of her personal time zone. Make no mistake: It’s always the one who’s late who holds all the power.