Pharrell made the world “Happy” in 2014 with this feel-good anthem. The song soared to #1 in 35 countries—it was the best selling song of 2014.

Pharrell wrote and produced “Happy” for the soundtrack of Despicable Me 2—it also became the lead single of his second studio album, G I R L. The song appears in a scene in the film where the lead character Gru dances through streets with joy because he has fallen in love.

Pharrell told W Magazine that “Happy” came after he unsuccessfully pitched Despicable Me 2 producer Chris Meledandri on some other songs he’d written.

After nine different songs, recorded fully, they were like, ‘No, no, no, no.’ So I went back and wrote ‘Happy.’ I didn’t have the melody, just the chorus. For 20 minutes after I finished, I was jumping around the room. I told Chris to listen to the song in his car, that if he didn’t like ‘Happy,’ I didn’t know what to give him.

Originally, Pharrell intended Cee Lo Green to sing the song—but things didn’t work out. He told Howard Stern:

Cee Lo Green wanted to do it—and he did do it. He sounded amazing on it. He burns my version! The powers that be, at the time, did not see it fit for him. Some folks on his team just felt that the priority should be on his album at the time, so they elected not to do that song. It’s not his fault; he was totally down with it. He was one of the most gracious people about it when ‘Happy’ came out

“Happy” is repeated 56 times over the course of the song. 62% of the “Happy” is dedicated to its catchy chorus—about 20% more than the average pop song.

The first-ever 24-hour music video was made for “Happy”—it follows 400 different people enjoying life while they walk around LA.