"I was living in a little flat at the top of a house and I had a piano by my bed. I woke up one morning with a tune in my head and I thought, 'Hey, I don't know this tune - or do I?' It was like a jazz melody. My dad used to know a lot of old jazz tunes; I thought maybe I'd just remembered it from the past. I went to the piano and found the chords to it, made sure I remembered it and then hawked it round to all my friends, asking what it was: 'Do you know this? It's a good little tune, but I couldn't have written it because I dreamt it."
Paul McCartney recounting how he wrote the song "Yesterday" in early 1964