Earworms are those nagging songs you find yourself humming on the bus.
In this programme, music presenter Shaun Keaveny meets fellow sufferers and scientists to find out why songs get stuck in our head. He asks songwriter Guy Garvey from Elbow how to write a catchy tune and discovers the Holy Grail of musicians everywhere - the 'earworm formula'.
For the past three years on his 6 Music breakfast show, Shaun has been asking listeners to send in their earworms. When psychologist Dr Lauren Stewart found out, she was fascinated by this strange mental phenomenon. Together they've compiled the largest study on earworms to date, with over 10,000 reports from people around the world.
Lauren and her team at Goldsmiths have found that some people are particularly susceptible to earworms. Plus they are starting to discover that certain songs are more 'earwormy' than others.
So is there a secret formula behind the world's catchiest tunes?
Producer: Michelle Martin.