I agree with "John Henry's Hammer" that this was "just one of those right place, right time things." Just the same you can increase the odds of it happening by knowing the right place and the right time. Pete Seeger lives in Beacon and this was a festival for political dissidents, so it is no real surprise that he showed up. Pete as you might know is an active member of the Sloop Clearwater, the local chapter of the War Resistors League, the Peoples Music Network, and the Beacon Sloop Club. If you start getting involved with those organizations you stand a much better chance of running into him than if you don't get involved.