Plot: In celebration of the series’ 40th anniversary on PBS, a stellar roster of diverse alumni gather to share their stories of what the series has meant to them, with reminiscences and performances by Julie Andrews, Audra McDonald, Don Henley, David Hyde Pierce, Josh Groban, Itzhak Perlman, Peter Martins, Patti Austin and Take 6, Elīna Garanča, and Michael Bublé.