Do you mean the Seattle Center Hootenannies at the Seattle Center in 1963? Not far from the big fountain. Some held in front of the Horiuchi mural, some in Center House. Before that, during the Seattle World's Fair in '62, Sunday afternoon multi-performer concerts at the United Nations Pavilion. Small fountain in the pavilion. I bellowed me li'l lungs out at both places.

". . . long, dark hair, long legs and a big smile." Hmm!!   

Don Firth