John Mellencamp seems to have stepped out from the pages of a Great American Novel. A grizzled patriarch conjured by Faulkner, perhaps.

Mellencamp, who is 70 this year and a three-times-married father of five, was born with spina bifida, which in the early 1950s was a terminal condition in the vast majority of cases. At six weeks, he underwent a pioneering surgical treatment that saved his life.

As soon as he was able to comprehend it, and thereafter, his beloved grandma Laura, who doted on him, told him he was the luckiest boy alive, “and don’t you forget it.”

Mellencamp, before the classics that would make him a household name.

Not so much luck but iron will, a miles-wide stubborn streak, and a near-pathological work ethic drove Mellencamp out into the world from Seymour, the small town in Indiana in which he was raised, and toward becoming an all-American rock star.

Early on, he suffered the indignity of having the name Johnny Cougar foisted upon him by David Bowie’s ex-manager. It took him a bunch of records to get good, but by the mid-1980s he had a string of multi-million-selling albums to his name, classics such as American Fool and Scarecrow. An authentic, blue-collar rocker, Mellencamp was tagged the voice of the heartland.

The path Mellencamp beat was never smooth, which is to say he proceeded along it kicking and screaming. He was self-disciplined and self-controlled to the extent he didn’t drink or do drugs, but not so much that he kept a lid on his volcanic temper. This, and the four packs of cigarettes a day he smoked, led Mellencamp to have a heart attack at 42.

He didn’t drink or do drugs, but Mellencamp became known for his nasty temper.

Researching my biography, Mellencamp, out this month, I spoke with many of the musicians who passed through his backing band. The great majority found themselves on the wrong end of the rock star’s eruptions more than a time or two. Kenny Aronoff, his long-serving drummer, likened the recording of 1982’s American Fool to “going to Vietnam. John was in a crappy mood. He got me so pissed off I jumped up and started throwing furniture at the walls.”

As it happened, once he’d attained superstardom, Mellencamp didn’t much care for it. Or, as he put it to me: “I found myself on top, but with nothing up there I was interested in.”

His second act has been ongoing for 25 years now. In this period, Mellencamp has transformed himself into a folk singer-songwriter in the grand tradition of Woody Guthrie. His latter-day songs, spooked spirituals and crepuscular ballads, prompted Johnny Cash to hail him as among America’s greatest living songwriters.

Mellencamp performs at Farm Aid 30, at FirstMerit Bank Pavilion, on Northerly Island, Chicago.

At the same time, he’s continued to champion the cause of America’s family farmers through Farm Aid, the nonprofit he co-founded in 1985 with fellow troubadours Willie Nelson and Neil Young. Mellencamp also composed a so-so musical, Ghost Brothers of Darkland County, with Stephen King, and pursued his passion for painting. (In 2019, his work was shown alongside Robert Rauschenberg’s at an ACA Galleries exhibition, in New York.)

In person, Mellencamp is striking and imposing. I was introduced to him at his home in Bloomington, Indiana, one hot summer’s day. He appeared to me like a figure hewed from rock: craggy, crumpled, Popeye arms as thick as slabs of meat.

Bowling over to greet me, he brandished a gnarled-wood Victorian walking cane topped with a gleaming silver handle. With a flourish, he pulled from it a three-foot-long rapier and, with a flick of his wrist, flashed it to within an inch of my left eye.

“You’ve got 60 fucking minutes,” he barked.

Paul Rees’s Mellencamp is out now from Atria