What are the six boards in music?

The "six bans" spread throughout the south of the Yangtze River. Because of its continuous development, change and renovation, the original old spectrum is called "old six boards" or "boss": the old six boards are simplified by subtraction and become "small six boards"; The original six-board notes are reduced and "accelerated" as appropriate, becoming "fast six-board ban"; The old six boards are reduced.