To mark the occasion, the Beatles were asked to write a simple song that would be understood by viewers of all nationalities. Writing began in late May, with Paul and John working on separate compositions, until John's All you Need is Love emerged as the obvious choice. The song not only had simple words and an uncomplicated tune but it perfectly captured the aspirations of international youth in the summer of 1967. This was the time when the war in Vietnam reached its height and the "love generation" showed their opposition by staging a number of peaceful protests. "It was an inspired song and they really wanted to give the world a message," said Brian Epstein. "The nice thing about it is that it cannot be misinterpreted. It is a clear message saying that love is everything."

In its call for universal love, All You Need Is Love extended the message that John had first tried to put across in The Word in 1965 to a worldwide audience. He was fascinated by the power of slogans to unite people and was determined to write something of his own with the timelessness of We Shall Overcome (a labour union song popularized in the Sixties by the folk singer Pete Seeger).

"I like slogans," John once said. "I like advertising. I love the telly." When asked in 1971 whether songs like Give Peace a Chance and Power to the People were propaganda songs, he answered, "Sure. So was All you Need is Love. I'm a revolutionary artist. My art is dedicated to change."

What viewers saw in Our World on June 25, 1967, was actually a recreation of a Beatles recording session: rhythm tracks had been laid down on June 14 and the live input was instantaneously added and mixed for transmission. A party atmosphere was created in Abbey Road's Studio One by inviting celebrity friends such as Mick Jagger, Marianne Faithfull, Eric Clapton and Keith Moon to sit around, hold balloons, wave placards and join in on the chorus. George Martin helped accentuate the message of international unity by opening the song with bars from the French national anthem, and closing it with snatches from Glenn Miller's In The Mood, Bach and Greensleeves.

The single was released on July 7, and became the soundtrack song for the Summer of Love, a paean to peace, love and understanding. "We had been told that we'd be seen recording it by the whole world at the same time," said Paul. "So we had one message for the world — love. We need more love in the world."