Pharrell Williams’ Happy is shaping up as the year’s mega hit: it has already risen to number one in 23 countries. But it’s also something of a rarity – a critically acclaimed song that is light, catchy and seemingly without ‘deep’ meaning.

Consider that of the nine best-selling songs of all time, most brim with melancholy, if not sadness and despair. Bing Crosby’s White Christmas, Elton John’s Candle in the Wind, Whitney Houston’s I Will Always Love You, Celine Dion’s My Heart Will Go On,– to paraphrase Elton, sad songs not only say so much, they sell really, really well.  But do listeners really prefer melancholy music, and if so why? Is Williams’ hit destined to lose its lustre when, years from now, we look back on the songs that mattered most in 2014?

The charts suggest we love tunes that rip our hearts out. The last blockbuster song that found success across genre, gender and generation the way Happy has was Adele’s 2010 tearjerker Rolling in the Deep. Williams’ song doesn’t aspire to that sort of gravitas. Its lyrics verge on throwaway simplicity; it’s built on a command to “clap along if you feel like a room without a roof.”

The lingering impression left by songs that put a smile on our faces is that they lack longevity.  The past hit most immediately suggestive of Williams’ smash −  Bobby McFerrin’s  Don’t Worry Be Happy − might have sounded good in 1988, when it went to number one in the US and won three Grammy Awards, but it hasn’t aged  well because it feels dated and contrived. Will Pharrell’s song suffer the same fate?

Pleasure pain principle

A study published last year in Frontiers of Psychology suggests it might. The researchers found that that sad music has a counterintuitive appeal – it actually makes people feel better. Sad songs allow listeners to experience indirectly the emotions expressed in the lyrics and implied by the (usually) minor-key melodies. The sadness may not directly reflect the listener’s own experiences, but it triggers chemicals in our brain that can produce a cathartic response: tears, chills, an elevated heartbeat. This is not an unpleasant feeling, and may explain why listeners are inclined to buy sad songs and why artists want to write or sing them.

While touring last year, Emmylou Harris would introduce her version of Felice and Boudleaux Bryant’s heart-breaking Love Hurts by saying that it began “my love affair with really dark depressing sad songs that have no hope.” Richard Thompson has described his penchant for writing downbeat songs by saying it’s actually pleasurable: “It's fun to sing sad songs. And it's fun to listen to sad songs. Enjoyable. Satisfying.”

Kelly Hogan titled her 2012 album I Like to Keep Myself in Pain. On the title track, Robyn Hitchcock’s lyrics assert that suffering is actually a heightened form of consciousness. Hogan explained: “Sometimes it’s just a great feeling to wallow in that because you do feel more alive.” How else to explain the decades-long popularity of blues, gospel and country, genres built on songs about hardship and heartbreak.

More than a feeling

But is it really sadness that listeners are connecting with or something more complicated? A recent study at McGill University found that emotionally intense music – whether sad or happy - stimulates the pleasure centre in the brain, in the same way that food, sex and drugs do.  The study found that listeners respond most forcefully to emotional complexity, a depth of feeling enhanced by clever arrangements that kept throwing out surprises, and the back-and-forth between tension and release.

Williams’ lyrics may be pretty straightforward, but he stacks Happy with small but rewarding melodic, harmonic and rhythmic inventions. He orchestrates handclaps into a polyrhythmic groove, while his falsetto vocal swerves gracefully through a cloud of harmonies. The bass line is so buoyant it practically blows soap bubbles.  

Last year Pharrell played a major role in another light but indelible hit, Daft Punk’s Get Lucky.  That song echoed classic disco – Chic’s Nile Rodgers played rhythm guitar, after all – a genre of music that was once dismissed by many naysayers as trivial. But now, thanks to Daft Punk and other electronic-music innovators, it’s become the equivalent of classic rock for many listeners who came of age in the last couple of decades, a tradition that should be celebrated rather than mocked as a fad.

It doesn’t hurt that Happy also feels like a sharp update of another master of feel good, Stevie Wonder.  For every schmaltzy tune that Wonder wrote in the happy zone – I Just Called to Say I Love You springs to mind as one that hasn’t worn well – there were three like Isn’t She Lovely?, You Are the Sunshine of my Life and Signed, Sealed, Delivered I’m Yours that have kept spines tingling for decades.

All of which means that after all these years the sound of sunshine may finally be getting its due, and Pharrell Williams, for one, couldn’t be happier.

Greg Kot is the music critic at the Chicago Tribune. His work can be found here 

If you would like to comment on this story or anything else you have seen on BBC Culture, head over to our Facebook page or message us on Twitter.