On a summer evening, I was pleasantly surprised by the brooding, gravelly voices echoing through the cozy and dimly lit Mash bar on E. Washington. In a back booth surrounded by chalk-covered walls, antique mirrors, and shiny wooden tables, I settled in to listen to the bluesy hits and rock-and-roll favorites of the laid-back duo Reeds & Steel. Highlighted by a single blue-tinted spotlight, Michael May (harmonica and vocals) and Adam Brode (guitar and vocals) exuded a gentle yet powerful style. Their mix of jazz-influenced blues and blues-rock, the gentle plucking of Brode’s guitar strings, and the brassy whine of May’s harmonica matched their chill aesthetic of rugged jeans and checkered flannel button-downs.

May’s harmonica elevated a jazzy, soulful rendition of Johnny Cash’s “Ring of Fire,” giving it a brazen sweetness that had me singing along. It was obvious from the claps and head nods around me that I wasn’t the only one reveling in their cheerful execution of the 1963 hit. Their slightly slower cover of Billy Joel’s “We Didn’t Start the Fire,” quite different from the frantic original, was also a fan favorite. Soulful and artistic, the soft strums of Brode’s guitar lulled us into a sense of untroubled satisfaction. They picked the pace back up again with rousing takes on some Cheap Trick favorites, lifting us out of our previous trance and into a state of cheerful merriment.

In more mellow songs, May and Brode easily transitioned to a crooning, softer tone that invited us into worlds of rocky marriages, lovesick melancholy, and long, brooding car rides down dimly lit roads that lead to nowhere, the harmonica’s sorrowful wail amplifying the heartache of the words. Their mournful yet still hopeful take on Jim Croce’s “I Got a Name,” along with Brode’s solo guitar riffs, were reminiscent of Croce’s live performances. Their covers of Prince favorites were heartfelt and genuine, with May’s harmonica adding emotion and sincerity.

Though their mellow personas and relaxed appearances make them seem easygoing and unbothered, this duo takes their craft seriously, and it shows in their music. They return to Mash Oct. 11 and 16.

Editor’s note: A previous version incorrectly identified David Roof as guitarist and vocalist instead of Adam Brode.