The singer began crying during a montage of fan-made videos for hit single 'Happy'

Pharrell Williams was reduced to tears by Oprah Winfrey when discussing the huge global success of his track ‘Happy’ – watch above.

During an interview on US channel OWN’s Oprah Prime last night (April 14), the singer was shown footage of fan-made videos for the track, and began to get visibly emotional about the impact and success the song has achieved since being release last November.

Speaking through the tears, Williams says: “It’s overwhelming because I love what I do, and I just appreciate the fact that people have believed in me for so long that I could make it to this point to feel that.”

Oprah then tipped Williams over the edge, bringing up his late grandmother, saying: “I was just thinking of your grandmother. I bet she didn’t even imagine that.”

The singer played a star studded set at the Coachella Valley Festival of Music and Arts in California last weekend (April 12).

Th singer was joined joined onstage by Snoop Dogg, Nelly, P Diddy, Gwen Stefani and Busta Rhymes during his show. Tyler, The Creator and Diplo also joined him onstage during his set.