Pharrell Williams has a solid handful of reasons to be happy in 2013. Here's one: "Get Lucky," the Daft Punk summer smash to which he lent his soul-splashed vocals. Here's another: "Blurred Lines," the inescapable Robin Thicke anthem he also sang on, while dodging much of the most pointed criticism despite logging a cowriter credit.

So he's opted to share his joy by throwing together a 24-hour interactive music video set to "Happy," his recent contribution to the Despicable Me soundtrack. It's streaming for 24 hours at 24hoursofhappy.com. (Of course, the song doesn't last 24 hours; the Flaming Lips already conquered that terrain. This one's looped. ) Featuring a constantly shifting set of models grooving in bliss to the track (the cast includes Steve Carrell and Magic Johnson), it's contagiously cheery. Had it not been so carefully put together, you'd think it was an attempt to one-up the recent interactive video for Bob Dylan's "Like a Rolling Stone."

Here's the link. But don't watch all 24 hours. That'd get dull fast. Just try and find the sweet spot. Here's one of several non-interactive four-hour versions that appear on YouTube: