Happy hitmaker Pharrell Williams has revealed that the number one song was originally recorded by Cee Lo Green.
Speaking in a radio interview with Howard Stern Pharrell said, "[Cee Lo Green] wanted to do it... and he did do it.
"He sounded amazing on it, he burns my version! But... how do I say this diplomatically? 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."
Pharrell added that Green took the songs worldwide success well, "There was a much bigger agenda [for him], he had an album to put out. 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."
Williams wrote and produced Happy which is on the Despicable Me 2 soundtrack.