Yesterday

The song is harmonically straightforward, based on a descending chord progression and relatively simple chord changes. Its effectiveness lies in its subtle shifts and melodic resolutions.

The song has a gentle, flowing rhythmic feel, primarily driven by McCartney's acoustic guitar playing and the subtle string arrangement.

The melody is memorable and emotionally expressive, built around a descending contour that mirrors the song's themes of decline and loss. It is highly singable and easily recognizable.

Paul McCartney composed the melody in a dream while staying at the Wimpole Street home of his girlfriend Jane Asher. Upon waking, he immediately played the tune on a piano by his bed to avoid forgetting it. For several weeks, he played the melody for various music industry figures to ensure he had not subconsciously plagiarized it, a concern he referred to as 'cryptomnesia.' The lyrics were eventually finalized with the replacement of the working title 'Scrambled Eggs' during a vacation in Albufeira, Portugal, in May 1965.

Originally released on the 1965 album 'Help!', this masterpiece features Paul McCartney backed by a string quartet, marking a sophisticated departure from the band's rock and roll roots. Its universal themes of regret and nostalgia have solidified its status as a timeless cultural landmark with over 3,000 recorded versions.