Rhythm of Destruction

The Doctor arrives on the uninhabited planetoid Quish, famous for having the biggest natural amphitheatre in the galaxy. The Blitzats Jazz Quartet are playing, but shortly afterwards the planetoid implodes. Everywhere they play they leave a trail of destruction in their wake – someone dies; a city is wiped out; an entire planet vanishes... But why - and how? The Doctor realises that the answer lies close to home.