Every time someone records Blowin' in the Wind or Mr. Tambourine Man, Bob Dylan makes seven and a half cents.
That might not sound like much. But in the exactly 50 years since his first, self-titled album came out on March 19, 1962, Dylan has written more than 300 songs as he's made his remarkable journey from hardcore folkie to cultural icon.
In the process, he has become one of the music industry's most "covered" songwriters, meaning his songs are widely recorded by other artists, in his case from Willie Nelson and Johnny Cash to Stevie Wonder.
But that acclaim by his peers and the media has not meant he has just sat back on his royalties and watched the river flow.
Dylan will be 71 in May, but he still spends a third of the year on the road, averaging more than 100 concerts a year, in what has often been called The Never Ending Tour.
"He still plays concerts, a lot of them B and C locations," says Toronto entertainment lawyer Lon Hall, a fan who travelled to a Dylan concert in upstate New York a few years back.
"He was playing to a crowd of maybe 600 people, almost all of them college students with an average age of 20."
Touring of course can be quite lucrative, but it is the songs Dylan has written that earn him the most money.
If a singer records All Along the Watchtower — one of the most covered rock songs of all time — and then sells just a thousand copies of the CD, that singer owes Bob Dylan $75. Multiply that by all the Dylan songs sold all over the world and you're talking real money.
That is just one of the reasons Bob Dylan is worth at least $80 million US, according to the best estimates of Dylan watchers and associates.
It's a significant sum, but still a far cry from the $630 million that former Beatle Paul McCartney was worth at the time of his divorce in 2008, according to the judgment. Or when compared to the $90 million that Lady Gaga earned in 2011 alone from album sales, tours and endorsements, according to Celebrity Networth website.
Dylan seldom gives interviews. His lawyer didn't return a call and his talent agent, Creative Artists in Los Angeles, had no comment on his wealth.
Because he is so secretive, he doesn't appear on Forbes Magazine's richest celebrity list, where the lowest celebrity earner makes $10 million a year.
But Dylan should easily have that beat. His biographer estimated he makes $15 million a year just on tours and one sports and entertainment lawyer, who asked to remain anonymous, said a net worth of $80 million is far too low.
"Eighty million isn't so much. If Dylan is the number one songwriter, he must be worth more. Royalties from songwriting are where the real money is in entertainment," said this man, from his office in London, U.K.
Beyond being what many have called the greatest songwriter of his generation, Dylan is also something of a workaholic.
"Dylan tours the world relentlessly, and is one of the hardest working live performers in music," wrote Howard Sounes, the author of Down the Highway: The Life of Bob Dylan, a 2001 autobiography that was updated last year.
"He is extremely wealthy, but chooses to live like a gypsy, spending more time on his tour bus than in any of the 17 properties he owns around the world.
"Eccentricity has enhanced the legend. It is one thing to be a genius; it is better still to be an eccentric genius."
It seems that there is nothing Dylan won't do. He has a radio program on SiriusXM satellite radio — Bob Dylan's Theme Time Radio Hour — and advertising contracts that shocked his old folk and hippie fans, like the one with Victoria's Secret, the lingerie firm.
Bob Dylan fans don't like it when their idol fiddles with his image and they have made that plain over the years.
In the 1960s he started out as folk singer but soon moved to the harder stuff: rock and roll.
His folk fans loved the protest songs such as Masters of War or The Lonesome Death of Hattie Carrol, when Dylan just sang and played the guitar.
But then he showed up at the 1965 Newport Folk Festival with an electric guitar and a backup group (The Band) and the purists booed him off the stage. They kept on booing during the tour that followed.
"Everywhere we went they booed us," Canadian musician Robbie Robertson, who toured with Dylan in 1965, told Sounes.
There was the same shock and horror when Dylan licensed The Times They Are a-Changing for an ad for the Bank of Montreal; it was even worse when he appeared in an ad for the racy lingerie firm, Victoria's Secret in 2004.
"Why on earth would Bob Dylan do this?" asked Seth Stevenson in Slate at the time.
The answer is that it introduced Bob Dylan to a new generation of listeners and sold albums. Yet another example of how the canny businessman Dylan changes with the times.
Positively rich street
"Bob Dylan is one of those people who isn't afraid to re-invent himself," says Lon Hall who represents people such as Deepa Mehta, the filmmaker. "He's not wrapped up in his own image."
His business acumen started young. Robert Zimmerman (his real name) arrived in New York City from Minnesota when he was 19.
A year later, in 1962, he changed his name to Bob Dylan and signed on with an agent, Robert Grossman. Grossman helped kick-start Dylan's career, in the process becoming a rich man himself.
The relationship ended in tears, or to be more exact, in court in the 1980s.
Dylan first big score was with Blowin' in the Wind, which he wrote in just a few minutes, he said, in April 1962.
Recorded by the folk group, Peter, Paul and Mary, it started Dylan on his way.
He soon bought property outside New York City and would eventually have a small real estate empire, along with his income from song writing and touring.
Among other bits of real estate, he owns a business complex in Santa Monica, Calif., a farm in Minnesota and a five hectare estate just north of Malibu.
His properties alone are worth at least $20 million, Sounes estimated.
But they don't seem to have changed the man all that much.
People do go into the music business just to make money, Dylan told a BBC interviewer once, in 1986, when he was in Toronto filming Hearts of Fire.
"That's a sad thing," he said, "because it changes the quality of the work being done."