Titled "Only One", it features background vocals and piano accompaniment by the former Fab Four, reported Ace Showbiz.
"Hello, my only one. Remember who you are. No, you're not perfect but you're not your mistakes," the rapper delivers the lyrics.
"I talked to God about you. He said he sent you an angel. And look at all that he gave you," West, 37, sings from the perspective of his mother Donda, who died from complications during surgery in November 2007.
McCartney and West first began working together in a small bungalow in Los Angeles in early 2014.