Like a cavalry army, the no-input mixer and feed-backing guitar are fluid and powerful but difficult to control precisely. Justin Asher's "Siege of Zhongdu" is an interactive, electronic feedback piece for a trio of no-input mixer and 2 feedback controlled stratocaster guitars played through hand held honeytone amps. The no-input mixer controls the output of each feed-backing guitar and integrates their sound in to the loops generated by the mixer, multiplying it's waves. The graphic score translates the long range movements of a 5 year siege of the ancient city of Zhongdu by the army of the infamous Mongol conqueror Genghis Khan in to sonic and physical movements of the trio. The result, like the siege, is violent, plotting and overwhelmingly successful.