A City Hall rally followed by two hours of impassioned testimony that include a man on his knees begging and a singalong to “Give Peace a Chance” failed to convince the San Francisco Recreation and Park Commission that it should allow a free 50th anniversary Summer of Love concert in Golden Gate Park. By a unanimous vote, the commission upheld the staff decision to deny promoter Boots Hughston a permit for his planned June 4 event at the Polo Field in Golden Gate Park. Citing concerns over public safety, traffic, lack of organization and a wildly fluctuating crowd-size estimate, Hughston was advised to find a partner with more concert promotion experience and submit a new application. Hughston says he has spent nine months on the event and planned to pay its $200,000 cost out of pocket. Because he had put on a 40th anniversary Summer of Love celebration in the park, he believed his permit probably would be granted and announced the concert a few weeks ago. Performers were to include Eric Burdon and War, and the original rhythm section of the Santana Blues Band. [...] his permit application had not been approved, and on Feb.