On March 9th, distinguished guests gathered at the home of Dr. Paul Sternand his wife Pat in Potomac to celebrate violin master Isaac Stern’s birthday onthe eve of his 80th birthday concert at the Kennedy Center. He officiallyturned 80 last July, but turning 80 entitles you to celebrate your birthday allyear long if you choose to, doesn’t it? Mr. Stern performed a concert onMay 10th, co-presented by the Washington Performing Arts Societyand the Kennedy Center, at the Kennedy Center Concert Hall.