How many episodes are there in Brother Long and Brother Hu's music classroom?

According to the query of Tencent Video APP, Chang Fei was the head teacher of the music classroom unit of Dragon and Tiger Brothers Variety, and Yu-Ching Fei and other interviewed artists were interviewed at random under the stage. This unit is very distinctive. The props used by Chang Fei are not only a pointer, but also an air flute horn.