“Let’s talk about Daddy for a second.”

Such a remark, between most siblings, wouldn’t raise an eyebrow. But when it left the lips of singer-songwriter Shelby Lynne, sitting in a tall director’s chair earlier this week at Book Soup in West Hollywood, just an elbow’s length away from her younger sister, musician-author Allison Moorer, the impact was breathtaking.

“Daddy” refers to Vernon Franklin Moorer, who showed up at the Frankville, Ala., home the girls shared with their mother, Laura Lynn Smith, after she had left her husband in 1986. Vernon shot his estranged wife to death on their front lawn before turning the rifle on himself while both girls hid inside the house.

Shelby was 17, Allison 14.

That 33-year-old tragedy is the focal point of Moorer’s new book, “Blood,” and the companion album of the same title she has just released. Together, they take readers and listeners through her extraordinary journey from a cowering child of an alcoholic, abusive father, through survivor of unspeakable tragedy to accomplished musician nominated for Grammy, Oscar, Academy of Country Music and Americana Music Assn. awards to, most recently, first-time author.

It’s why Moorer was at Book Soup, where Lynne moderated the L.A. stop on the “Blood” book tour, the only time the sisters — who call each other “Sissy” — are scheduled to meet and discuss their past in public.

“Daddy was a major book reader,” noted Lynne, 51 and a Grammy-winning artist, “and it’s been running over in my mind for weeks now: What would he think about us sitting here right now, in Book Soup, talking about your book? And I think, ‘Well, asshole, you missed that!’ ”

Sisters Shelby Lynne, left, and Allison Moorer discuss Moorer’s new family memoir, “Blood,” at Book Soup on Nov. 18.

(Carolyn Cole / Los Angeles Times)

A day earlier, over breakfast at a restaurant a short distance down Sunset Boulevard from Book Soup, Moorer, 47, elucidated the difference between her original motivation for writing “Blood” and what it came to represent for her, transcending her initial idea of creating a narrative she could share someday with her son, John Henry, who is 9.

“This book is not a historical document,” she said in the gentle Alabama drawl she shares with her sister. “What I know now is that I wrote the book so that I could do the work I needed to do [on myself] in order not to repeat my parents’ mistakes,” she said, “and so that I could be a better parent for him.”

Far beyond simply conveying the details of her parents’ volatile relationship — the quintessential co-dependent relationship between an abusive alcoholic and his victim, who feared leaving because her husband threatened to kill not just her but both their daughters if she did — “Blood” masterfully develops its narrative with a rhythm and flow that make Moorer’s musical acumen evident on virtually every page. Moorer pulls no punches in addressing a family dynamic that ultimately turned fatal.

If the structural elements weren’t clue enough, she also drops in astute musical references periodically.

“I write these things down to simultaneously put us to rest and keep us alive,” she notes midway through the book. “I won’t solve anything by doing this job I’ve assigned myself. I can’t reverse time even if I count backward from four to the tempo of ‘Thirteen’ by Big Star,” name-checking Memphis’ great ‘70s rock group fronted by Alex Chilton.

Moorer first gained recognition in the pop music world with her 1998 debut single “A Soft Place To Fall,” a song she wrote with Gwil Owen and which actor-director Robert Redford heard, instantly loved and incorporated into his film “The Horse Whisperer,” earning her an early-career Oscar nomination for best original song.

Allison Moorer performs her song “A Soft Place to Fall.”

Although that musical opening salvo by and large was a farewell to a love interest, it’s hard not to connect the opening line to her family tragedy from a decade earlier: “Daylight has found me here again / You can ask me anything, but where I’ve been.”

She scored her highest chart success with “Picture,” a 2001 duet with Kid Rock, issued as an alternative to the original recording between Rock and co-writer Sheryl Crow, when Crow’s record label initially declined to allow its release.

In “Blood,” both the book and the album, Moorer conveys deep emotion, considerable wit and insight about herself as well as illumination about her parents’ strengths and weaknesses. At the heart of it all: her abiding bond with Lynne, with whom she realized a mutual long-held goal of recording a full album together two years ago, “Not Dark Yet.” Her late-in-the-game decision to write and record a musical companion piece to her book, Moorer said, means that a planned follow-up to that duet album “has been shelved for now.”

The seed for the book was planted shortly after Moorer gave birth in 2010 to John Henry, while she was married to Texas singer-songwriter Steve Earle. They divorced in 2015, an experience that informed much of her previous solo album “Down To Believing.”

Shortly before her son turned 2, he was diagnosed with autism, and caring for him has pushed her music career into the background. In realigning her life, she started work on the book, and at the same time earned a master of fine arts degree from the New School in New York. She said writing could serve as a creative outlet she could manage from home while focusing on being a mom and perhaps open the door to a career in teaching.

Allison Moorer performs her song “Blood”

“After I had John Henry, I got a call to be on [poet-author] Maya Angelou’s radio show,” she said. “We were having a conversation about my childhood, and she said, ‘Well, now you have John Henry. What are you going to tell him about it when he’s old enough to ask?’ And I didn’t know; I didn’t have an answer for that. And for whatever reason, that comment put in me this seed. I didn’t know then what it would turn into.”

Thus, about the time she turned 40 in 2012, she decided to initiate a deep dive into that tragedy and its long-reverberating impact.

Both women have been lauded by critics for the forthrightness and power of their songwriting, which Moorer carries over effectively into the narrative of “Blood,” punctuating the central story with what she refers to as “interstitial pieces” that amplify certain themes or provide emotional counterpoint to others.

In the second of the book’s three main chapters, titled “Sissy,” Moorer describes her: “Sissy has always been brave. Primed and ready is an understatement — she, in some ways, searches out and craves the comfort of confrontation. We want what we know.

“What Sissy knew was disapproval and anger,” the passage continues. “She’d heard, just as I had, Daddy accuse Mama of being unable to give him a son, so she tried her best to be the one he seemed to want … . She played music with him, hunted and fished with him, and often put herself in between him and Mama.”

Moorer acknowledged that the book shines what could be uncomfortable light on Lynne as well as herself in telling their story, so she thanked her sister in front of a couple of dozen onlookers crammed into the cozy corner that Book Soup uses for readings. Returning the compliment, Lynne said, “I’m so proud of her for doing this,” as she headed out the bookstore’s back door at the end of the session, as Moorer lingered behind to meet attendees and sign their books.

Along for the ride were Moorer’s husband, Texas singer-songwriter Hayes Carll, and his parents, who had flown in from Houston and planned to look in on the siblings’ joint appearance Wednesday at the Grammy Museum.

“What I’m getting back from the world is heavy,” Moorer said of the initial public response to the book and the album, a song cycle that lays out the arc of this part of her life story from youthful discovery to emotional defeat to salvation. “People are suffering because, for whatever reason, they don’t feel like they can tell their story. They don’t feel heard.

“They don’t feel like they have anywhere for their story to go,” she said. “They don’t know how to tell it, they don’t know whom to tell it to. But in this age, I think people are becoming more willing to tell the truth and to be open. It’s a wonderful development.”