Many traditional instruments underwent changes in the early to mid 20th century which has a profound effect on the performance and sound of Chinese music. A western equal temperament is now used to tune most traditional instruments, which to modern ears seem less harsh and more harmonious but which also robs the instruments of their traditional voices. To ears now used to hearing modern tunings, even Chinese ones, traditional tunings can sound out of tune and discordant.
In order to accommodate Western system, changes were made to the instruments, for example in the pipa the number of frets was increased to 24, based on the 12 tone equal temperament scale, with all the intervals being semitones.
There is also a need to standardize the tuning when the instruments are played in an orchestra, which in turn may also affect how the instrument is made. For example, traditionally dizi is made by using a solid piece of bamboo which made it impossible to change the fundamental tuning once the bamboo is cut. This issue was resolved in the 1920s by the insertion of a copper joint to connect two pieces of shorter bamboo, which allows the length of the bamboo to be modified so that minute adjustment to its fundamental pitch can be made. The Xindi, “new flute”, is a 1930s redesign of the Chinese flute incorporating western influences on the basis of equal temperament.
In order to achieve a greater vibrancy and loudness with instruments (not to mention longevity), many string instruments are no longer strung with silk but with steel or nylon. For example, metal strings began to be used in place of the traditional silk ones in the 1950s for pipa, resulting in a change in the sound of the pipa which became brighter and stronger.