The 37-year-old rapper - who has 18-month-old daughter North with wife Kim Kardashian West - was speaking about his fashion teacher Louise Wilson, who was a professor of fashion design at Central Saint Martins College of Arts and Design in London and who died last year, when he started sobbing on BBC Radio 1.
In an interview with Zane Lowe, he said: "I went to Louise Wilson's memorial. The greatest fashion instructor of all time. And I'm talking about of all-timers, if we're talking about Paul McCartney, then we have to talk about Louise Wilson.