Released on Oct. 9, 1987, “Tunnel Of Love” has a reputation among some Springsteen fans as his “soft rock, baby boomer divorce record.” It’s true that “Tunnel Of Love” doesn’t exactly rock, and it’s definitely not guitar-heavy. Instead, it’s dominated by synthesizers, drum machines, and Springsteen’s weary, mature croon.If you care about lyrics, “Tunnel Of Love” is every bit as gut-wrenching as “Nebraska.” And the music suits those lyrics — this is an introspective record, and the contemplative music inevitably sends the listener inward, evoking a sleepless night filled with various shades of blue poring through a bedroom window, the kind that a married person looks out as he or she wonders why in the hell their spouse still isn’t home at 2 a.m. To talk about “Tunnel Of Love,” I called up John Darnielle, who started writing and recording songs under the moniker of the Mountain Goats in the early ’90s. Since then, he’s earned a reputation as one of the best songwriters in indie rock, known for a literary style that, like Springsteen, touches both on autobiographical material and, more notably, fictional characters who are sketched out with flesh blood authenticity.