Modular Musical Instrument. Each module (1 octave, 12 dynamic keys ) can be used individually in stand-alone mode or assembled with others composing a full piano keyboard. The same object can be used for studio writing or recording, then musicians can use 1 or 2 octaves, or for live performances, then they can use 7/8 octaves. The modularity of the tool reduces its size, and thus favors the transportability. The electronics of each item is based on a arduino uno card. The prototype is composed by 4 octaves.