IS EVERYBODY “HAPPY”? NBC fittingly used Twitter yesterday to announce that Pharrell Williams will become a coach for the show’s seventh season this fall. "Okay, we can OFFICIALLY say it! WE ARE SO #HAPPY to announce PHARRELL WILLIAMS = #NewVoiceCoach for SEASON 7," the tweet read. Pharrell did a star turn as a guest mentor for Usher’s team last year, and the show’s more voluble viewers have been lobbying for his return on social media ever since. “His dominance in record sales in 2014, coupled with his incomparable accomplishments in the world of fashion and design, make him an irresistible addition to The Voice family," offered NBC Entertainment’s Paul Telegdy. "He has already made a considerable impact as a mentor, drawing on an impressive track record as both a producer and performer. It is a perfect fit for The Voice as we evolve and reach for new heights with this franchise. It feels like we are welcoming an existing family member home." Williams retweeted the NBC tweet with the words, "This is going to be so fun." (4/1a)