According to the official website of the Chinese Musicians Association, there are two versions of the piano piece Four Little Swans Dance, the simple version is for piano grade two, and the complex version is for piano grade six. The piano piece Tying the Red Headband is the first level of difficulty for the exam. The higher the level, the more difficult it is. So the piano piece Four Little Swans Dance is difficult.
A piano piece is a piece of music played on a piano, sometimes with other instruments playing at the same time.