Take away the greasy dreamboat charm and the predilection for Viceroy cigarettes, and Mac DeMarco’s calling card might be his choice of guitar tone. He likes his six-strings slippery and gleaming, like a forehead that hasn’t been washed in a few days. After being relegated to the background on recent single “Passing Out Pieces.” DeMarco’s signature sound is back in force on the newest track cut from his upcoming full-length, Salad Days, the sweet slacker anthem “Brother.” It’s a surprisingly melancholy advice column of a track, a piece of reflection in a mirror stained with bong water. Don’t let the weathered ball-cap or unkempt exterior fool you: There’s a heart of gold underneath that grime, and the tenderness of “Brother” is proof.