In the structure of the electronic organ, there is no major or minor, and the major or minor is played. Modal is a group of sounds (usually within seven tones) organized according to a certain relationship, and connected into a system (i.e. tonic) centered on a certain tone. This system is called modal.

The major scale consists of seven basic tones. The composition rule of major is that the interval size between each tone is "full-full-half-full-full-half" in turn, which is the composition rule of major. For example, in C major, do, re, mi, fa, so, la and xi, in which the interval relationship between do and re is full, and re and mi are also full.

Minor is also a mode composed of seven tones, and each major has its own minor. We can think of minor as another scale parasitic on major. Move the tonic in this major down three degrees, and you can find the tonic in its minor. Take C major as an example. Its minor is A minor. The composition rules of minor scales: the interval size between each tone is "full half full half full" in turn. For example, la, xi, do, re, mi, fa in A minor, where xi and do, mi, fa are semitones, and the rest are full tones.