Every year on the Isle of Struay, there is a grand concert, where the islanders play fiddles, recite poetry, and sing and dance in front of their friends and neighbours. This is a major social event in a small community like Struay. Katie Morag is very excited indeed, and she plans to sing her favourite song. Arriving for the concert too, are Katie Morag's uncles, Sven and Sean, who are world-famous musicians and utterly identical. Nobody on Struay can tell them apart. On the big evening, one of the pair loses his voice and it is down to Katie Morag McColl to save the concert from disaster.