1, staff:

In the staff, tone sandhi does not necessarily represent black keys, but black keys can only be represented by tone sandhi.

Black keys in the staff: XB = # C = BD, # D = BE = BBF, XE = # F = BG, # G = BA, # A = BB = BBC.

2, white spectrum:

In the white spectrum, the changing sound level must represent black keys, while black keys can only be represented by changing sound level.

White spectrum black keys: # C = BD, # D = BE, # F = BG, # G = BA, # A = BB.

Take the 6 1 key electronic organ as an example. A * * has six groups of keys, of which the first to the fifth groups from the left are complete, each group has 12 keys, and the rightmost group is incomplete, with only one C (that is, dol in C key).

These six groups of keys are, from left to right, big group, small group, small group 1, small group 2, small group 3 and small group 4. Starting from the leftmost key of a large character group, the white keys are C, D, E, F, G, A, B, and 1, 2, 3, 4, 5, 6, 7 among the keys corresponding to C.

Extended data:

Black and white keys on piano or electronic organ is divided according to the law of twelve averages. The temperament that divides an octave into twelve equal parts (semitones) is called the twelve average law.

A semitone is the smallest pitch distance in the organization of the twelve average laws. A tone whose distance between two tones is equal to two semitones is called a whole tone. There are twelve semitones in an octave, that is, six whole tones. In the middle of a series of basic tones, except for E to F and B to C which are semitones, the distance between the other two adjacent tones is full tones.

On the piano, two adjacent keys (including black keys) form a semitone, and two tones separated by a key form a whole tone. There is no black keys separation between E and F, and between B and C. In addition, the distance between the other two adjacent tones is a whole tone, which needs to be separated by black keys. In this way, seven white keys and five black keys appear in an octave.