Yesterday" is a song originally recorded by the Beatles for their 1965 album “Help!”. Although credited to "Lennon–McCartney", the song was written solely by Paul McCartney. It remains popular today with more than 2,200 cover versions, and is one of the most covered songs in the history of recorded music. "Yesterday" was voted the best song of the 20th century in a 1999 BBC Radio 2 poll of music experts and listeners and was also voted the No. 1 Pop song of all time by MTV and Rolling Stone magazine the following year. This song was the first official recording by the Beatles that relied upon a performance by a single member of the band (McCartney, accompanied by a string quartet). The final recording was so different from other works by the Beatles that the band members vetoed the release of the song as a single in the United Kingdom (however, it was issued as a single there in 1976).

"Yesterday" is a melancholy ballad about the break-up of a relationship. 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.