◆ On the electronic organ, 1234567 folds seven singing names, all on the white keys. To identify the key of C 1, we only need to look at the distribution of black keys: in each group of sounds, black keys is arranged according to the rule of two or three, and the white key of the two on the left and the one on the left of black keys is the key of C 1, and the tone is 2 3 4 5 6 7 to the right in turn.

Black keys is the chromatic key of the white key (also the chromatic key of the white key on its right side), and black keys is the key used only when there is a rising or falling tone or tone sandhi in the score, which is seldom used by beginners.

◆ For a more intuitive explanation of the position of 1234567 on the keyboard of the electronic organ, as well as the sound names (CDEFGAB) and volume names (1234567) of each scale, please refer to the following figure at a glance: