The former Beatles legend – who agreed to pay Heather a staggering $130 million divorce settlement following a bitter public battle earlier this year – has teamed up with electronic music star Nitin Sawhney to record the acoustic ballad entitled "My Soul."
Sawhney said: "Paul has done a track about how he feels about Heather and what was going on with the paparazzi because no one has heard his side of it at all - so this will be the first time anyone hears a song relating to that subject. It's a very emotional and very powerful song."
A friend of the musician added to the MailOnline website: "What the song shows is that rather than feeling embittered towards Heather, Paul just feels sorry for her."
"He feels sorry that she was never able to tell him the full truth about her past life. He feels that their romance happened so fast and so publicly that a lot never really got said."
"Paul knows Heather is a complex person, and deeply misunderstood - but that she has hardly helped herself by being less than transparent about her life."
Lyrics on the heartfelt ballad include Paul singing about how Heather helped him cope following the death of his first wife Linda in 1998, and phrases such as, "We could climb every mountain, swim through every sea. When the all world is asleep we could set ourselves free."
The song will appear on Sawhney's new record "London Undersound," which will be released in October.
