Volume two of Rhino’s Hi-Five EP series finds Gram Parsons and Emmylou Harris braiding those high-lonesome harmonies with the kind of eerie congruence that usually comes from either siblings or lovers. But where their voices locked with an airtight flawlessness on 1973’s GP, by 1974’s Grievous Angel, Parsons was on a more slippery slope thanks to some well-documented indulgences. Still, their chemistry together is uncanny, as evidenced on the Bakersfield-tinged opener, “Return of the Grievous Angel,” where the duo’s simmering passion and restraint make lyrics about hanging out with amphetamine-riddled truckers, heroin-kicking hipsters and alcoholic rednecks all somehow seem romantic. Inspired by George Jones’ breathtaking ballads, “$1000 Wedding” plays the heartstrings with reckless abandon, pushing the tear-in-beer honky-tonk formula so far that Parsons’ palpable pain can be felt every time his voice breaks. Other gems include a backstage acoustic rehearsal of “Sin City,” the country boogie-rocking “Ooh Las Vegas, a sparser version of “Hickory Wind,” and a re-master that makes everything sound incredibly up-close and intimate.