NEW YORK, N.Y. - Johnny Carson didn't invent late night television or its talk shows. He didn't invent their desk-and-couch format, or the monologue, the sidekick, the obligatory house band. Even many of his most popular comic characters were lifted brazenly from other performers, such as Jackie Gleason and Jonathan Winters.
So what set Carson apart? Why is he unrivaled by any other TV comedian or late-night star? What made him a trusted, enduring, influential and altogether likable presence unmatched by anyone in the history of the medium except, arguably, Walter Cronkite and Oprah Winfrey?
Finding out is the mission of "Johnny Carson: King of Late Night," a two-hour "American Masters" portrait premiering Monday on PBS.
With his debut as host of NBC's "The Tonight Show" 50 years ago this October, until his exit on May 22, 1992, Carson was seen by more people on more occasions than anyone else in U.S. history.
Carson reigned for nearly 30 years, hosting 4,531 episodes and receiving 23,000 guests. For most of his run, he had no competition, or none that mattered. His nightly viewership, averaging as much as 15 million, was more than the current audience of "Tonight" successor Jay Leno and CBS rival David Letterman combined.
But who was he? "King of Late Night" does a fine job of penetrating the familiar veneer of Carson, a private man in spite of his exposure.
He grew up in small-town Nebraska, the son of a father who worked at the local power company and an emotionally withholding mother whose approval he seems to have sought, fruitlessly, his entire life.
But as a boy, he discovered the way to win approval — at least from others — was by performing magic: "You can be the centre of attention without being yourself," he explains as an adult.
This led to showbiz as his chosen profession. And after college, he landed a job at an Omaha radio station, where, with the advent of TV soon after, he hosted a program on the infant medium. A 1950 film clip captures him at work, blinking and breathless behind his desk — much in contrast to the cool, unflappable on-air manner he would grow into.
Soon he went to Los Angeles, where he hosted a sketch-comedy show on a local station. He scored a prime-time network show on CBS, but it flopped. Then he retreated to New York in 1957 to host a daytime quiz show for also-ran ABC.
During his five years on "Who Do You Trust?" he was able to establish himself as an attractive, quick-witted personality, while building bonds with his chosen sidekick, Ed McMahon, who, of course, would remain at his side for the rest of his career.
Hired to replace the departing Jack Paar on "The Tonight Show," Carson made his first appearance on Oct. 1, 1962. No video exists of his debut, just an audio tape that finds him sounding cool and confident even as he jokes about his jitters.
"King of Late Night" follows Carson from there all the way to his retirement from the show in 1992, and his death, at age 79, in 2005.
Narrated by Kevin Spacey, "King of Late Night" is written, directed and produced by Emmy- and Peabody-winning filmmaker Peter Jones, who for years wrote an annual letter to Carson seeking his co-operation in the creation of a documentary about him. Carson always declined, but after his death, Jones successfully approached Carson's nephew, Jeff Sotzing, who controls his uncle's archives.
The film hears from dozens of performers and colleagues, as well as from the second of Carson's four wives, Joanne.
"This is a guy who was as familiar as a bedtime story," says Arsenio Hall. Hall, whose syndicated show arrived in 1989 to become Carson's only real threat, is lavish in his praise of Carson as an interviewer: "He had the perfect barometer in his head for when to go and when to stay out. He could save you if the show needed it, or he could let you do your thing."
In addition, he was a superb stand-up comic.
There were jokes that zeroed in on current events, including this mid-1970s gem that, four decades later, seems as topical as ever: "President Ford is considering an income-tax cut for people in lower tax brackets. The bad news is, he still hasn't figured how they can get an income."
But ultimately, Carson's popularity wasn't based on his interview skills. Or his jokes.
"I don't think anybody was watching Johnny Carson to rate how his material was," says Conan O'Brien, himself briefly a "Tonight Show" host. "You liked him. You liked that man so much, and you went with him."
The closest anyone has come to filling Carson's role in the culture was Oprah Winfrey for the quarter-century she hosted her weekday talk show. Now, there is no one.
When Carson left "The Tonight Show" behind, Jerry Seinfeld says, "that show never existed again. There never was a 'Tonight Show.' It was Carson."
Frazier Moore is a national television columnist for The Associated Press. He can be reached at fmoore(at)ap.org and at http://www.twitter.com/tvfrazier