Thanks to Tom Ewing's exhaustive scholarship, I know the precise day that I saw Bill Monroe. It was June 24, 1979, and it was at the Southeastern Wisconsin Bluegrass Festival. It's right there on page 375 of Bill Monroe: The Life & Music of the Blue Grass Man.

The date and location had long since slipped out of memory. Ever since that Sunday afternoon, however, I have remembered that as his mother and I drove back to our home in a North Shore suburb of Chicago, our son, recently turned 7-year-old Alex, offered the observation that the most impressive of the performers he'd seen was "that man called Bill." Bill Monroe had that effect on just about every sentient being who heard him. On stage as well as on record, Monroe always seemed larger than life.

In fact, in moments of morbid reflection, I have found myself thinking of what it would be like if I lived in some dystopian state in which I could listen to only a single artist. In that idle speculation Monroe's name inevitably pops up as a leading candidate. One does not tire of exposure to his many talents as singer, mandolinist and songwriter. Elvis Presley's first single was of Monroe's "Blue Moon of Kentucky," the most famous example of his influence on the first generation of rock 'n' rollers. Buddy Holly was a fan. Jerry Garcia, Bob Dylan. Others, too.

Ewing's is the second full-length Monroe biography but by far the definitive one. The first was Richard D. Smith's Can't You Hear Me Callin': The Life of Bill Monroe, Father of Bluegrass (2000), and right there you're learning something Ewing doesn't tell you. In the preface (p. viii) he passingly mentions "a biography that I didn't feel was adequate," after which it vanishes into the memory hole, absent even from the bibliography at the end. Ewing's treatment is nearly twice as long as Smith's (which I read with pleasure at the time of its publication), and it is staggeringly well researched. Ewing himself, a guitarist and vocalist, was among the last of the Bluegrass Boys, Monroe's legendary band.

Born on Sept. 13, 1911, in western Kentucky, Monroe died Sept. 9, 1996, in a nursing home north of Nashville. Ewing traces the family roots back to Scotland (paternal) and the Netherlands (maternal). Both Monroes and Vandivers were established in the Appalachian region before the Revolutionary War. A descendant of the latter, the fiddler Pendleton Vandiver, became Bill's beloved "Uncle Pen," by which name this appealing man is honored in one of his nephew's most admired songs. Uncle Pen, along with Bill's older brothers Birch (a fiddler) and Charlie (guitarist), shaped his melodic imagination, steeped in old Kentucky traditions and transposed to the mandolin. Intensely musical, the family was poor and struggled to get by. Young Bill had an often contentious relationship with his brothers.

Birch, Charlie and Bill joined the Southern diaspora, ending up in northwest Indiana to work in the factories. Bill and Charlie took to performing as the Monroe Brothers. Signed to the Bluebird label, they cut 10 songs in two hours in a Charlotte studio on Feb. 17, 1936. Though successful as an act, the two Monroes quarreled and in the summer of 1938 went their separate ways. Still, the songs they recorded, 60 in all and in good part traditional, would survive to this day in the repertoires of folk singers and bluegrass bands.

Bill formed his own band and played in Georgia and the Carolinas to a growing audience. He would always insist that bluegrass was invented in Greenville, South Carolina, in the summer of 1939, when he found himself in the company of the right musicians to carry out his musical vision.

"In forming the other instruments around the mandolin and my singing," he would recall, "it turned out to be bluegrass music," though it wouldn't be called that for another decade, after Lester Flatt and Earl Scruggs became Blue Grass Boys for a time and the style spread into other groups. The most immediately popular of them was Flatt & Scruggs' Foggy Mountain Boys. Ewing quotes musician Everett Lilly, who played with that band, as saying, "The public named bluegrass music ... through the fear to speak Bill's name" to Flatt & Scruggs whose parting from Monroe, hardly amicable, left bitter feelings for more than two decades afterwards.

Bill and bandmates debuted on the Grand Ole Opry on Oct. 28, 1939. His radically innovative approach to the stringband tradition astonished Opry veterans like Uncle Dave Macon, Roy Acuff and just about everybody who heard it. Soon Bill was signed to Columbia Records, and the rest is ... well, the story of an immensely gifted, complicated, difficult man who over the course of a long career, with many ups and downs, cast a spell that fell beyond the bluegrass hard core.

In this long examination of Monroe's life and times, Ewing misses little. He meticulously records the arrival and passing of band members (pages 471-477 catalog every one of them) and follows Monroe's marriages and numerous affairs (mostly prominently with Bessie Lee Mauldin and Virginia Stauffer; the latter wrote the Monroe classic "With Body & Soul"). Ewing records the travels, the performances, the exasperations of life on the road (not least a touring bus called "Bluegrass Breakdown," which often broke down), the finances, the feuds and reconciliations. He also details the shaping of various Monroe songs and instrumentals as well as the backstory to older, non-original folk, parlor and country material that filled the rest of the repertoire. There is also plenty on Monroe's intersection with the mid-century folk revival (which rescued his career as bluegrass was falling out of fashion in Nashville's commerce-obsessed music industry) and with country, rock and pop artists.

There is also, towering above it all, the character of Bill Monroe, usually aloof, even selfish, possessed of a rarely practiced sense of humor, yet capable of unexpected acts of kindness and generosity. If no one ever called him a nice guy, few -- these mostly ex-wives and ex-lovers whose grievances Ewing treats with sympathy -- thought of him as a monster either. Over the years, as he became known as the Father of Bluegrass, he grew ever more revered, though no less Bill Monroe.

This story has been told before, but never before so definitively as Ewing has related it in these pages. No doubt it helps that the author knew Monroe personally and professionally, enough to respect him and also enough to assess him with dry eyes. The distribution of genius seems random, and its beneficiaries are as often as not ordinary people with the usual assortment of virtues and vices, wisdom and cluelessness. Except for his extraordinary talent, creativity, and determination which led him to places and experiences only a select few can claim, he was the sort of man whom we all have met, but probably not befriended, at one time or another. He was not, happily, given to the sorts of behavioral excesses and social aggressions biographers of Hank Williams and Woody Guthrie, two contemporaries who match Monroe's standing in the American pantheon, have documented.

For the rest of us, he was Bill Monroe, the man who fashioned a musical genre of his own and thus enriched the lives of all who stopped to listen. In the end that is all that matters. The rest is biography, and I doubt there will ever be one that improves on Ewing's.