This 1965 hit, Yesterday is yet another Beatles song which I associate with Singapore. There is a very nice wailing bit, ".... long for yes-ter-day yeah yeah yeah, yes-ter-day." which anyone can join in, however inebriated. Somehow this type of Beatle song strips an idea to its very bones. In those days in 1965 of two-year commissions there were a lot of young men doing their service in the Far Flung and getting their "Dear Johns" (not exactly the worst thing that could happen, but distressing enough). Yes, Sir! Yesterday" struck a chord in many a breast of those young servicemen. The version that I play can be found in Beatles Songs for the Recorder.
According to the biographers of Paul McCartney and the Beatles, McCartney composed the entire melody.

Lyrics