Among loquat and pipa, why did people who played pipa in Song Dynasty make jokes?

Because he can't tell a pipa from a loquat.

The difference between "loquat" and "pipa" is:

First, the nature is different. 1, Loquat: a Rosaceae plant with leaves named after pipa instruments. 2. Pipa: It is the first plucked instrument and a plucked instrument.

Second, the use is different. 1, Loquat: Edible, ripe Loquat is sweet and nutritious. 2. Pipa: Play music, play the melody of music, and accompany other musical instruments.

Third, the form is different. 1. Loquat: the leaves are leathery, lanceolate, oblanceolate, obovate or oblong, 12-30cm long and 3-9cm wide. Apex acute or acuminate, base cuneate or gradually narrowed into petiole. The upper edge is serrated, the base is full, the upper surface is bright and wrinkled, and the lower surface is densely covered with grayish brown fluff. The fruit is spherical or rectangular, 2-5 cm in diameter, yellow or orange, with rusty fur outside. 2. Pipa: It consists of "head" and "body". The club head includes chord groove, chord shaft and mountain pass. Body includes phase, taste, sound box, hand cover and other parts.