According to
this article, YouTube's Music Vault channel will be releasing loads of live content...
The Music Vault channel was launched in April by Wolfgang’s Vault, which is an online memorabilia store that carries everything from posters to photography to—you guessed it—live recordings. The videos were collected from a number of sources, including the archives of legendary concert promoter Bill Graham, The King Biscuit Flower Hour (a radio program that was dedicated to live rock and roll), as well as famous festivals like Woodstock and the Newport Folk Festival.
Maybe the Day on the Green show does exist?
The company has stated that the 13,000-plus videos are not all it has to share, and that more are on the way, all to keep eyeballs glued to YouTube.