Pharrell Williams says everyone should be able to celebrate joy - including Iranian youths who were arrested for posting an Internet video of them dancing to his song Happy.
The young people were arrested recently, as some in Iran see the video as promoting the spread of Western culture, and Iranian laws ban women from dancing in public or appearing outside with heads uncovered.
Singer Pharrell said he has "the utmost respect for people's religious views" and doesn't know much about Iranian law.
But he added: "The present is a gift, and if you just want to celebrate your happiness, you should be allowed to do that."
Speaking at an exhibit opening in Paris on Monday, he said: "They are just dancing."
Fans have posted similar Happy videos from around the world, showing people dancing down streets.