This weekend is the 40th anniversary of the Woodstock Music & Art Fair, and if the young billionaires who’ve amassed fortunes via YouTube, Facebook, and various other exercises in selling crowds to themselves for free are grateful, well, they should be. The three-day gathering in upstate New York was a watershed moment in the history of American business, and while the music acts that played there may be wrinkled, gray, and largely forgotten, the entrepreneurial principles pioneered there are still extremely relevant.

Woodstock began with a tiny classified ad placed in The New York Times on February 1, 1967. “Young man with unlimited capital to invest looking for interesting, legitimate investment opportunities and business propositions.”

The young man was 23-year-old John Roberts, then a recent graduate of the University of Pennsylvania… More…