The Songwriting Process

Wikipedia describes how Paul McCartney dreamed the melody to “Yesterday” and then set it to nonsense lyrics:

According to biographers of McCartney and the Beatles, McCartney composed the entire melody in a dream one night in his room at the Wimpole Street home of his then girlfriend Jane Asher and her family. Upon waking, he hurried to a piano and played the tune to avoid forgetting it.

McCartney’s initial concern was that he had subconsciously plagiarised someone else’s work. As he put it, “For about a month I went round to people in the music business and asked them whether they had ever heard it before. Eventually it became like handing something in to the police. I thought if no-one claimed it after a few weeks then I could have it.”

Upon being convinced that he had not robbed anyone of his melody, McCartney began writing lyrics to suit it. As Lennon and McCartney were known to do at the time, a substitute working lyric, titled “Scrambled Eggs” (the working opening verse was “Scrambled Eggs/Oh, my baby how I love your legs”), was used for the song until something more suitable was written.

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McCartney said the breakthrough with the lyrics came during a trip to Portugal in May 1965:

“I remember mulling over the tune ‘Yesterday’, and suddenly getting these little one-word openings to the verse. I started to develop the idea … da-da da, yes-ter-day, sud-den-ly, fun-il-ly, mer-il-ly and Yes-ter-day, that’s good. All my troubles seemed so far away. It’s easy to rhyme those a’s: say, nay, today, away, play, stay, there’s a lot of rhymes and those fall in quite easily, so I gradually pieced it together from that journey. Sud-den-ly, and ‘b’ again, another easy rhyme: e, me, tree, flea, we, and I had the basis of it.”

Source: Wikipedia