Customizable electronic musical instrument and user interface

A customizable electronic musical instrument comprising:

• a staircase mounting frame comprising:
• a plurality of mounting openings, the mounting frame for securing a plurality of electronic musical modules in a staircase configuration, wherein the plurality of electrical musical modules comprises at least two keyboards in the staircase configuration, wherein each of the electronic musical modules is interchangeably secured in one of the plurality of mounting openings of the staircase mounting frame;
• wherein the plurality of electronic musical modules at least includes:
• a first type of electronic musical module for generating one or more real-time control signals responsive to user operation,
• a second type of electronic musical module for generating audio signals in response to at least one of the one or more real-time control signals,
• a third type of electronic musical module for processing the audio signals to generate electrical signals, and
• an arrangement for attaching a strap, the strap enabling the customizable electronic musical instrument to be worn by a user;
• and
• at least one instrument interface adapted to transmit the electrical signals from the third type of electronic musical module to an external system.