Pharrell Williams celebrates birthday with Spongebob

Los Angeles: Pharrell Williams celebrated his 41st birthday party in a Spongebob Squarepants theme. The `Happy` singer, who turned 41 on April 4, donned a black and yellow varsity jacket, jeans, and the green version of that infamous hat as he posed for pics on the yellow carpet.

Joining the singer to celebrate his birthday were guests including designer Alexander Wang, Swizz Beatz and Alicia Keys, photographer Terry Richardson, Q-Tip, and Soledad O`Brien.