When Paul McCartney composed the tune for "Yesterday," the song seemed familiar to him and he asked many others if they recognized it before he felt comfortable recording it. Many have suggested that "Georgia on My Mind" is the song which most resembles McCartney's tune.
Ray Charles was Nilsson's favorite singer and McCartney one of his favorite songwriters.
Harry Nilsson demonstrated the similarity of the two songs by performing them as a medley:
"Yesterday" / "Georgia On My Mind" Medley by Harry Nilsson