It's a long one, the first installment in a two-part series. Topics of discussion: Paul's love of Scotland, how technology has dramatically improved the concert experience, the greatness of The Beatles, and The X Factor.
Paul says he thinks about them every day and revealed he's even "visited" by John when writing new songs.
He said: "John and George were real mates. I have a huge fondness for them.
"They were both part of my life and who I am. There are little reminders of them all the time.
"Today, somebody brought me a new book by 1960s photographer Duffy and I saw a picture of John in it.
"Now, if I write a song, I'm always cross-checking in my mind, 'Would John have let me write that line or is it just too soppy?'
"Sometimes, I just think, 'Too bad, it's my song.' But I'm always cross-checking with him."