Four-in-one: one of the eight great songs of Jiangnan silk and bamboo. Four-in-one is the name of a musical instrument, which means it is composed of many musical instruments. This song, also called Bridge, is a comprehensive Daqu composed of silk and bamboo materials.

There are different versions of Four in One Ruyi, such as Su He, Hang He, Yang He and so on. Among them, Shanghai is the most popular, and it is a large divertimento composed of eight tunes. Including Tang, Yu Erlang, Qiao Lianhuan, Yunyang Board, Emergency Wind, First Sale, Second Sale and Third Sale.

The music begins with a loose board, and the adagio is the deceleration and flower addition of "36". The biggest feature of this song is the "selling" in the second half, which is played independently by various silk and bamboo instruments in turn. Players can improvise and compete with each other, so it is also called "competition". The transition between players is natural and smooth, interspersed in the ensemble, which becomes interesting and changeable. Finally, the silk and bamboo are singing together, rendering a lively and festive atmosphere.