Pharrell Williams' 24-hour music video is a whole lotta Happy Pharrell's Happy footage is uplifting, and acts as a giant clock that users can click between. It's been quite a year for sunny-voiced American producer and singer/rapper and entrepreneur Pharrell Williams. In June Williams, 40, joined an exclusive club of artists to hold the No.1 and No.2 positions on the US Billboard single charts simultaneously; he co-starred in Robin Thicke's controversial but popular song Blurred Lines and Daft Punk's worldwide smash Get Lucky. This week GQ magazine named him its "hitmaker of the year." Now Pharrell has topped it all off with the music world's first 24-hour pop music video, for his new single, Happy. Pharrell Williams creates 24 hour music video in world first, for single Happy. While the idea reeks of gimmickiness - the song itself is only four minutes long, meaning you'd have to hear it 360 times to watch the whole thing - stick with it, because there's plenty going that makes it worthwhile to watch for 15 minutes at least. For a start, the footage is uplifting. Even determined curmudgeons should feel the clouds lifting while watching a beaming African-American girl as she grasps on to a colourful bunch of balloons, or a tiny boy in khakis grooving up the street like a young Michael Jackson. The video is really 360 separate clips of smiling men, women and children freestyle-grooving to the song as they walk towards the camera in ordinary city locations including footpaths, parks, hotels, laneways and building foyers. Most of the performers are unknowns, although there are stars: Magic Johnson, Steve Carrell, Jamie Foxx and Jimmy Kimmel, among others. An impressively limber and co-ordinated Pharrell himself joins the fun in one version. Having watched for about an hour, this writer had not spotted Julia-Louis Dreyfus' Seinfeld character Elaine, infamous for her woeful dance moves. The lyrics to Happy are childishly simple, but suit the clip beautifully. The chorus begins: "Clap along if you feel like a room without a roof / clap along if you feel like happiness is the truth." Whether Pharrell meant it that way, the effect is a panacea to so many earnest grainy video art pieces we've all tried to make sense of in dim gallery side rooms. Pharrell has undeniably made genuine video art with heart and humour, so this has to be considered a landmark for the music video. By rights it should also appear near the top of the list for non-pharmaceutical treatments for depression. But can there be too much of a good thing? Does eating that whole tub of chocolate-chip-fudge-cookie ice-cream make you sick? How about the whole shelf from the freezer section at the supermarket? You will work that out for yourself within half an hour of watching Happy. Rest assured, web parodies are being made as you read this. But it's equally certain a music TV channel somewhere will already be toying with the idea of playing the whole thing. And even if you don't want it all, even a couple of rotations are enjoyable. One thing is for sure - it's a brilliantly clever way of embedding his song deep in listeners' memories. Even when you close off the video, the song will keep playing over and over in your head.