Excuse me, the exercise of harmony course is how to play a tetrachord in the big score table with four notes in the bass and treble score tables respectively.

1. Generally, the left hand plays the bass spectrum with two fingers, and the right hand plays the treble spectrum with two fingers.

2. In the case of close arrangement, you can also play the lowest note with your left hand and the first three notes with your right hand.

3. When the two notes of the bass spectrum exceed octaves, first play the lowest note with the left hand (5th finger), and then play the above three notes with the left hand (1 finger) and the right hand (semi-decomposed).