Here it is! The show will be televised first on Thursday July 30th. Check your local listings:
http://www.pbs.org/wnet/gperf/episodes/pete-seegers-90th-birthday-celebration-from-madison-square-garden/preview-pete-seegers-90th-birthday-celebration-from-madison-square-garden/793/
I'm guessing but I'll bet you can watch it on line too.