Which documentary featured cameos by musicians, Go Further or The True Glory?
Go Further:  The film features cameos by Dave Matthews, Natalie Merchant, Ken Kesey, Bob Weir (of the Grateful Dead), Michael Franti (of Spearhead), Anthony Kiedis (of Red Hot Chili Peppers), Rob Heydon, Medeski Martin & Wood, and The String Cheese Incident. The True Glory: The True Glory (1945) is a co-production of the US Office of War Information and the British Ministry of Information, documenting the victory on the Western Front, from Normandy to the collapse of the Third Reich.
Dave Matthews, Natalie Merchant, Ken Kesey, Bob Weir (of the Grateful Dead), Michael Franti (of Spearhead), Anthony Kiedis (of Red Hot Chili Peppers), Rob Heydon, Medeski Martin & Wood, and The String Cheese Incident