Sir Paul McCartney and Kanye West perform on single for rapper's daughter

Sir Paul McCartney plays the organ on a song dedicated to Kanye West's daughter. Credit: Charles Guerin/ABACA USA/Empics Entertainment

Sir Paul McCartney has joined forces with Kanye West on a new single dedicated to the rapper's daughter, North West.

The new song called 'Only One' is reportedly an 'emotional' ballad featuring auto-tuned vocals and organ music played by Sir Paul.

Kanye takes on the voice of his mother, Donda West, who died in 2007, and addresses both himself, using his middle name Omari, and his baby daughter who was born in 2013, using her nickname Nori.

The soft 'emotional' ballad is dedicated to Kanye West's daughter with Kim Kardashian. Credit: Reuters/Gonzalo Fuentes

A statement from Sir Paul on his official website said: "For any of you guys who were wondering what I was doing with Kanye ... Here it is: Only One. Happy rocking new year!"

Kim Kardashian also tweeted her approval for the new song.

The single is exclusively available on iTunes.