THE AHERN BROTHERS The Ahern Brothers (self-released) If they were indeed brothers, Josh Rennie-Hynes and Steve Grady would, presumably fight like cats and, well, other cats (like the Everlys) and maybe toss up which one would be the drunk and which one the abstemious one (ala the Louvins). Or maybe they’d just offer a few years of sublime togetherness that suggested sibling closeness and then decades of acrimony that almost made a mockery of those matched voices (in the mann