Music Performance System

A method of reusing a first data structure comprising the steps of:

• creating a first data structure related to a song, wherein the first data structure comprises a first type of digital information, and the first data structure can be used to produce a musical output;
• using a first version of a second data structure along with the first data structure to produce a first modified musical output;
• using a second version of the second data structure along with the first data structure to produce a second modified musical output;
• wherein the same first data structure is used to make both the first modified musical output and the second modified musical output and wherein the first modified musical output is different than the second modified musical output.

A method of generating a musical output comprising the steps of:

• retrieving a pristine digital bit stream related to a song;
• retrieving a second type of digital information;
• using the pristine digital bit stream and the second type of digital information to generate a second digital bit stream, the second digital bit stream representing a musical signal;
• using the second digital bit stream to create the musical output and playing the musical output in real time;
• receiving a command from an operator during the playing of the musical output, the command modifying the musical output.