Thus, Peking opera is not a monolithic form, but rather a coalescence of many older forms. However, the new form also creates its own innovations. The vocal requirements for all of the major roles were greatly reduced for Peking opera. The Chou, in particular, rarely has a singing part in Peking opera, unlike the equivalent role in Kunqu style. The melodies that accompany each play were also simplified, and are played with different traditional instruments than in earlier forms. Perhaps most noticeably, true acrobatic elements were introduced with Peking opera. The form grew in popularity throughout the 19th century. The Anhui troupes reached their peak of excellence in the middle of the century and were invited to perform in the court of the Taiping Heavenly Kingdom that had been established during the Taiping Rebellion. Beginning in 1884, the Empress Dowager Cixi became a regular patron of Peking opera, cementing its status over earlier forms like Kunqu. The popularity of Peking opera has been attributed to the simplicity of the form, with only a few voices and singing patterns. This allowed anyone to sing the arias themselves.