Why do songs get stuck in our heads? And what makes some tunes stickier than others?

Drs Rutherford and Fry investigate 'earworms', those musical refrains that infect our brains for days. Every morning 6Music DJ Shaun Keaveney asks his listeners for their earworms, and Hannah finds out which tunes keep coming back.

Adam asks Dr Lauren Stewart, from Goldsmiths University, to reveal the musical features that make some songs catchier than others.

And they find out why, in times of crisis, an earworm may just save your life.

Producer: Michelle Martin.