Robert Plant once referred to Shemekia Copeland, daughter of Texas blues legend Johnny Copeland and nearly a star in her own right these days, as the next Tina Turner. To these ears, her golden voice and knack for interpretation sound more like a summit meeting between Mavis Staples’ righteous sexiness and Aretha Franklin’s righteous anger, but whatever. Bottom line, she’s just that impressive, and if you haven’t gotten the news four albums down the line, well, you’ve probably stopped reading.

There’s a difference this time around, however; like last year’s Talking To Strangers, which featured the production and guiding hand of Dr. John, this new CD is also mentored by a roots-rock powerhouse: guitarist Steve Cropper, who gives a professional (but never slick!) sheen to her latest studio set. And yes, he plays on it. In case the title hasn’t tipped you off, this is Shemekia’s bid for soul respectability.

That she has the vocal and emotional range to pull it off is already without question. But there’s a disturbing mediocrity to many of the originals on The Soul Truth, one that makes Copeland sound like she’s saying a hell of a lot more than she is. As on her previous albums, they were mostly co-written by longtime mentor John Hahn, but here they rarely rise above the lyrical and musical clichés found in “Better Not Touch”: “You can look, but you better not touch / keep your hands off Miss Such-And-Such / I don’t think that’s asking way too much.” Is Hahn not quite up to taking on Memphis soul? Or is he just faltering? Hard to say.

Cropper’s contributions help, especially on the pure Memphis ballad “Poor, Poor Excuse,” but overall, the standout moments are the ones where Shemekia tackles outside material, particularly Eddie Hinton’s “Something Heavy” (a daring folk-blues with the accent on the folk), Cropper’s own “Honey Do That Voo-Doo,” and the best track here, a duet with Dobie Gray on Bekka Bramlett’s “Used.” It may be unreasonable to expect this fiery young upstart to tackle, say, Dan Penn or Willie Mitchell material, but if it’s good enough for Tina and Aretha, and given the comparisons, well… why not?