Geoffrey Mason reports: The event was free speech fundraiser organized by International Times (or IT for short), which was a London underground newspaper in print only at the time. Now it exists on-line only.
They did coverage of it leading up to the show and after April 1967. I've attached a nice large version of the cover of their special 14th Hour Technicolour Dream special (issue #12) here. You would probably want to link to their archived version of the issue: IT - International Times Archive [Link]
I've also attached 2 clippings from the issue of previous (#11) issue of IT giving some details of the event.
I've attached a newspaper advert for the event.
I've attached two color flyers for the event, but I don't know who designed them. The first horizontal one certainly looks like Mike McInnerney's work, but I am not sure.
BBC documentary series "Man Alive" has a video covering it that aired about 3 weeks after the event: [Link]
There was a 90-minute documentary "A Technicolour Dream" about it released from Eagle Rock Entertainment in 2008: [Link]
Monday, January 9, 2017 12:25 PM
The famous '14-Hour Technicolour Dream" show. And The Syn, who did not play, wrote a song about it!
Complete list of bands: Alexis Korner Barry Fantoni Champion Jack Dupree Charlie Browns Clowns Christopher Logue Denny Laine Dick Gregory Gary Farr Giant Sun Trolley Ginger Johnson and his African conga drummers Glo Macari and the Big Three Graham Bond Graham Stevens Jacobs Ladder Construction Company Jean Jaques Lavel Jimmy Powell & The Five Dimensions John's Children Lincoln Folk Group Mike Horovitz Noel Murphy Pete Townshend Pink Floyd Poison Bellows Robert C. Randall Ron Geesin Sam Gopal's Dream Savoy Brown Simon Vinkenoog Social Deviants Soft Machine Suzy Creamcheese The Block The Cat The Crazy World of Arthur Brown The Creation The Flies The Interference The Move The Pretty Things The Purple Gang The Stalkers Tomorrow Utterly Incredible Too Long Ago To Remember Sometimes Shouting At People Yoko Ono