It’s always good for artists to get out of their comfort zone every now and then, but when you’re fixtures in the bluegrass world, like the Gibson Brothers have been over the past two decades, that notion probably isn’t as easy as it sounds. Too far a left turn and you certainly run the risk of alienating those fans you’ve cultivated over the years. But the two brothers did change things up a bit on their 14th album Mockingbird , starting with nabbing The Black Keys’ Dan Auerbach and David “Fergie” Ferguson (Johnny Cash, John Prine) for production duties. Most notable this time around is the duo’s desire to play around with a handful of different genre styles—sometimes subtly, sometimes rather blatantly. On “Lay Your Body Down,” a song about pining for someone while driving all night in a pickup truck, they channel early-‘70s rock radio a la the Eagles. “Sweet Lucinda” is a slow, oozy country ballad that champions a woman who won’t give up on her man. And “I’m a Better Man” is a mid-tempo number that could’ve been cribbed from a Hall & Oates outtake; it’s sultry and smooth, complemented by a sweet string section. The surprise of the 11-song set though comes toward the end, with a passionate cover of R.E.M.’s tearjerker “Everybody Hurts.” It’s a bit odd, but the Gibson Brothers make it work. And it’s indicative of where they are now—challenging themselves to break new ground after years of mastering one.