MIDI commands formulation for chord music application (Case study: Major and minor chord)

Generally, playing music tones can be done in two ways, melody and chord. Chord is a harmonization of three or more pitch that sounding simultaneously. In MIDI, one command only for sounding one tone. For chord, need three or more command that run together. If implemented in an application, the formulation is required. So MIDI commands can be generated by the program without having to write MIDI commands one by one manually.