When she was a kid, Rosanne Cash wanted to become a writer, not a singing star who was always away from home like her famous father, Johnny Cash.

Of course, she gave in to the family tradition, becoming a Grammy-winning singer/songwriter with 11 No. 1 country hits, but she eventually became a writer, as well, publishing a short-story collection, a children's book and essays in the New York Times, Rolling Stone and Martha Stewart Living.

Whether she pens prose or songs, Cash is a wordsmith of uncommon emotional depth.

Her albums "Interiors" (1990) and "Black Cadillac" (2006) are deeply penetrating discussions of divorce and death, respectively. "The ocean's calm outside my door/the storm rages inside my head/In perfect control so no one could know/I smile but I'm not even there," she sings on "Land of Nightmares" on "Interiors."

In "Composed," her just published memoir, Cash offers long, eloquent passages about her innermost thoughts, but often the succinctness of a songwriter enables her to deliver a terrific one-liner. For example, at age 20, she moved to London to work as a record-company go-fer, as arranged by her father. Instead of finding herself, Cash found loneliness and despair. A female friend in London read Rosanne's diary and apologized for how difficult things were for her.

Three decades later, Cash reflects: "I hated her for knowing more about me than I knew about myself."

"Composed," a slim but compelling and inspiring book, walks the line between memoir and autobiography.

A memoir, says Minneapolis memoirist Laurie Lindeen, is "a slice of the pie rather than the whole pie."

But in the loosely chronological "Composed," Cash gives us the whole pie -- just not always the filling that we crave.

At times, she is wonderfully revealing and brilliantly insightful, with vivid, poetic descriptions of what was going on in her mind. Her account of her 2007 brain surgery is as dramatic and harrowing as a Hallmark movie minus the two-hanky sentimentality. These kinds of segments evoke the rapture of Bob Dylan's superlative 2004 memoir, "Chronicles: Volume One."

Elsewhere, however, Cash dismisses key elements of her life with less probing than "Entertainment Tonight." For instance, she calls "Walk the Line," the 2005 biopic of her drug-addicted dad, "an egregious oversimplification of our family's private pain, writ-large and Hollywood style" and does not elaborate. As for her own involvement with drugs, she gives that a sentence or two without any specifics or amplification. And she never really explains why her marriage to Nashville star Rodney Crowell dissolved. But she goes into Carrie Bradshaw-like detail about what she wore to the funerals of her stepmother, father, stepsister and mother.

"Composed" is aptly titled because it is steadfastly gracious, never dishing dirt or dissing anyone but offering many gratuitous shout-outs to musicians and friends who did right by Rosanne.

A top-notch editor, like a great record producer, would have demanded more. Or maybe less. Instead, at age 55, Cash just listened to her own voice.

Jon Bream is a Star Tribune music critic and author of biographies of Prince, Led Zeppelin and Neil Diamond.