From shortbread tins to the Royal Mile, rugby games and highland weddings, the bagpipes have long been a symbol of Scottish identity: but where did they come from, what are they for, and who writes their music?

With pipers Simon McKerrell and Brighde Chaimbeul, Tom Service explores their history against the backdrop of global piping traditions from Sweden to Macedonia, Spain and Hungary. What's the difference between the ceol mhor and the ceol beag? Are modern pipes more likely to be made from goat or gore-tex? And how did they make their way into everything from AC/DC to Eminem, and Berlioz to Bach? Tom is on the case...