Pharrell Williams has struggled to contain his emotion as he met a couple who played his song Happy at their son's funeral.

The music star was on Dutch TV show RTL Late Night when he was introduced to the family, who told him how his hit song had affected them and how they had played it at the funeral of their son, after he died in an accident.

Pharrell had recorded a video message for the grieving couple and when he got to meet them in person on the show he was visibly moved, fighting back tears as they thanked him for his message and his song, and what it represented.

After the mother talked, the star had to take some deep breaths and at one stage leaned over with his hands on his knees, apparently to compose himself.

"That was quite a surprise and once again I'm humbled," he said.

He later said to the parents: "I am so honoured that anything of mine could have helped to lighten up that day and helped to give any kind of positive influence to the thought and that ritual of laying him to rest."