Chilling audio clip of Erich Leinsdorf telling a Boston Symphony audience about JFK assassination

Fifty years later, this 30 second audio clip still gives me chills - It is the moment in which conductor Erich Leinsdorf, informed an afternoon Boston Symphony audience about JFK's assassination 

I have been looking for it every since I heard it as kid, when it was a clip on an LP record "Chet Huntley And David Brinkley: A Time To Keep: 1963 - Voices And Events Of The Year" - found it finally