Imagine.. Yoko wrote Imagine

In reality, the Imagine refrain was coined by Yoko Ono in reaction to her childhood in Japan during the second world war.

Released in September 1971 in America and a month later in the UK, the title track of Lennon's Imagine album is one of the world's best-loved songs. After the singer was shot dead in New York in December 1980, it reached the top of the singles charts in Britain.

Ono has now revealed her key role in the song's creation. She says it was inspired by trying to use her imagination to create a better world for her and her brother during the war.

She describes how as a 12-year-old she used the power of imagination to try to alleviate their plight as her country was bombed. They had been evacuated from Tokyo but were desperately short of food.

I'd imagine menus for my starving brother. He would start to smile. The power of imagination is so strong. If you think something is impossible, you can imagine it and make it happen, she said.

The Imagine refrain can be found in several of her poems written in the early 1960s before she met Lennon. A collection was published in her book Grapefruit in 1965.

Lennon himself admitted that Ono should have been jointly credited for the song. In an interview two days before his death, he said he had been too macho to reveal her role.

He said: Imagine should be credited as a Lennon/Yoko Ono song. A lot of it, the lyrics and the concept, came from her. Straight out of her book, Grapefruit. Imagine this or imagine that.

The significance of his comments was lost in the aftermath of his death. Ono's poems, which she calls instruction pieces, include lines such as imagine a raindrop, imagine the clouds dripping and imagine a goldfish.

Ono also talks about the composition and writing of the song in 1971. It was done mainly at Tittenhurst, the mansion near Ascot in Berkshire where the couple lived. The rest was composed on a plane journey, she said.

Ono has previously said of Imagine: It crystallised his dream for the world, it crystallised his idealism and it was something that he really wanted to say to the world. She has never before spoken of how it was partly inspired by her own poetry.