Theoretically, it is required to comply with the "Twelve Average Laws" (Twelve Average Laws are a very reviewed physical and mathematical problem).

In fact, there is no 100% match.

For example, the change of temperature will affect the melody of piano, and the instability of voltage will affect the pronunciation of electronic organ.

However, the tuning rules of these instruments strictly abide by the "Twelve Average Laws" (except toy electronic organ).

In addition, midi keyboard is a tool for inputting (writing) midi signals, which is incomparable to piano and electronic organ, such as writing drum rhythm. Some midi post-processing is applied to "minutes" (a semitone is equal to 100 minutes).