Talking about their recent collaboration, Sir Paul McCartney calls Kanye West "a monster... a crazy guy that comes up with great stuff”.

He also reveals that Oprah Winfrey warned him, "you shouldn't do this," after hearing West's track All Day; and how his contribution to the song FourFiveSeconds - which also features Rihanna - was sped up after he left the studio.

Sir Paul was talking to John Wilson for BBC Radio 4's Mastertapes.

Sir Paul McCartney's Mastertapes interview is available now on the BBC iPlayer and Red Button. It will be broadcast on BBC Radio 4 this Saturday, 28 May.