A 1959 promo shoot in a rock quarry put Ira and Charlie Louvin in crisp white suits in front of a 12-foot plywood devil that Ira built himself, with kerosene-soaked tires burning just out of frame. That image, the cover of Satan Is Real, captures the contradiction at the center of this episode: a duo with some of the most devout, precise close harmonies in country music, sustained by a partnership in chaos. Raised in Henagar, Alabama on Baptist shape-note singing, the brothers born Loudermilk moved from gospel to secular country, recorded “The Get Acquainted Waltz” with Chet Atkins, and reached the Opry in 1955.

The hosts break down the voice-exchange technique in which Ira’s high tenor and Charlie’s lower part crossed mid-phrase, and set it against Ira’s drinking, temper, four marriages, the mandolins he smashed on stage and glued back together sober, and the night his third wife shot him six times. Charlie ended the duo in 1963; Ira and his fourth wife were killed by a drunk driver on Highway 70 near Williamsburg, Missouri on June 20, 1965, when he was 41. The episode closes with Emmylou Harris’s 1975 hit “If I Could Only Win Your Love,” the Byrds cutting “The Christian Life” for Sweetheart of the Rodeo, the 2001 Country Music Hall of Fame induction, and the Grammy-winning 2003 tribute album.

• How shape-note singing trained the brothers in the architecture of harmony
• What “voice exchange” is and why it sounds like an audio optical illusion
• Why the mandolin-smashing cycle became the metaphor for Ira’s life
• Was the gospel sincere or a marketing gimmick? The case for music as a lifeline
• Why 1960s counterculture artists were drawn to two conservative gospel singers