Emotion got the better of Pharrell Williams in an interview with Oprah Winfrey.
The superstar singer-producer was reduced to tears on the OWN show, which aired in the US, when Winfrey showed him a montage of videos created by fans from around the world performing their own version of his Number One anthem Happy.
Watching the tribute, the 41-year-old hitmaker became visibly overcome and unable to speak, until Winfrey passed a tissue to him.
Dabbing his eyes, he asked "Why am I crying? I don't know."
"It's overwhelming because I love what I do and people have believed in me for so long that I can make it to this point, to feel that," he added.
The singer revealed that the multi-million-selling single wasn't even getting radio airplay until its video was released and people began to post their own versions on YouTube. From then on, he said, "it was no longer my song".