several other high-profile musicians. Lennon performed his Beatles composition "Yer Blues" towards the end, with an improvised vocal performance by Ono rounding out the set. The film would not be released until 1996, due to the death of The Rolling Stones' founding member Brian Jones a few months after it was shot. Early collaborations, marriage and "Bed-Ins" During the final two years of the Beatles, Lennon and Ono created and attended public protests against the Vietnam War. They collaborated on a series of avant-garde recordings, beginning in 1968 with Unfinished Music No.1: Two Virgins, which notoriously featured an unretouched image of the two artists nude on the front cover. The same year, the couple contributed an experimental sound collage to The Beatles' self-titled "White Album" called "Revolution 9", with Ono contributing additional vocals to "Birthday", and one lead vocal line on "The Continuing Story of Bungalow Bill", marking the only occasion in a Beatles recording in which a woman sings lead vocals. On March 20, 1969, Lennon and Ono were married at the registry office in Gibraltar and spent their honeymoon in Amsterdam, campaigning with a week-long Bed-In for Peace. They planned another Bed-In in the US, but were denied entry to the country. They held one instead at the Queen Elizabeth Hotel in Montreal, where they recorded "Give Peace a Chance". Lennon later stated his regrets about feeling "guilty enough to give McCartney credit as co-writer on my first independent single instead of giving it to Yoko, who had actually written it with me." The couple often combined advocacy with performance art, such as in "bagism", first introduced during a Vienna press conference, where they satirised prejudice and stereotyping by wearing a bag over their entire bodies. Lennon detailed this period in the Beatles' song "The Ballad of John and Yoko". During the Amsterdam Bed In press conference, Yoko also earned controversy in the Jewish community for claiming during the press conference that, "If I was a Jewish girl in Hitler’s day, I would approach him and become his girlfriend. After 10 days in bed, he would come to my way of thinking. This world needs communication. And making love is a great way of communicating." It was acknowledged that some Nazis, including Nazi "First Lady" Magda Goebbels, had Jewish lovers at one point in their lives. Lennon changed his name by deed poll on April 22, 1969, switching