Beth Hart first teamed up with guitarist Joe Bonamassa in 2011 and the partnership proved to be mutually beneficial. Hart gave the rock-edged Bonamassa some blues bona fides while the guitarist brought the vocalist to a wider audience. Plus, it was evident from their two studio albums and live set that the two had an easy chemistry: They shared a similar vernacular in Chicago blues and classic soul. The pair rely on that effortless interplay on Black Coffee, their third studio collaboration. Working with producer Kevin Shirley -- a veteran of Black Crowes records who has been in the Bonamassa orbit since 2006 -- the pair eschew straight traditionalism for a clean, colorful, retro vibe. Sometimes, the duo make choices that are perhaps a little too obvious -- the covers of LaVern Baker's "Saved" and Howlin' Wolf's "Sittin' on Top of the World" are a bit on the nose -- but they also know how to kick up the intensity on these chestnuts while avoiding sounding like they're on steroids. Still, the highlights of Black Coffeeare the originals and lesser-known songs, as they reveal that there is plenty of common ground between Hart's testifying and Bonamassa's shredding. Interestingly, that common ground feels formal in a way their individual solo albums don't -- respectively, Hart will delve into the personal spins on roots music while Bonamassa will indulge in blues myths -- but that's the appeal: They're working on keeping the flame burning, and Black Coffee may be their most effective testament in that effort to date.